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HomeMy WebLinkAboutemail Laumer about amendment with attachmentsPage 1 of 12 Malone, Walter From: Bozynski, Tony Sent: Friday, July 18, 2008 2:37 PM To: Malone, Walter Subject: FW: Widening University Ave FYI -----Original Message ----- From: Day, Bryan Sent: Friday, July 18, 2008 12:04 PM To: Bozynski, Tony; Beck, Steve; Hood, Mike; Henry, Bill Subject: FW: Widening University Ave From: Laumer, David "Bud" [ma ilto: bud. laumer@arkansashighways.com] Sent: Friday, July 18, 2008 9:44 AM To: Ron Rizzardi; coreen frasier; Weston, Steve Cc: Day, Bryan; Judy and Ken Gould; Mayor Subject: RE: Widening University Ave Let me start out by saying that this comment is my own as a land use planner and not anything I vetted through AHTD. I also have to start by saying that I have not seen any design work and do not know the project. So, this is just me adhering to the part of the Planner's Code of Ethics that says I should support communities in land use planning activities. I would also point out that you need to contact Steve Weston regarding anything to do with Safe Routes to Schools, so I will not comment directly on that program. In my opinion, we all need to learn how to use bicycles and feet for transportation. It is something that our ancestors knew how to do, but after well over half a century of auto domination we have collectively forgotten how to do it. We know how to walk or ride a bike for recreation, but transportation requires connections across a community and that is where we tend to get it wrong. A great intersection standing on its own is not nearly as valuable as a less visible series of connections that allow movement by foot or bicycle between destinations. What do I mean? The lack of shoulders or curbs and walks on P Street between Pierce and Polk (deep ditches & narrow street) are a serious impediment to walking or biking to the neighborhood school regardless of which side of University you live on. As a policy planner I like to spread the focus as broadly as possible before making specific recommendations. Recent work in the field tends to support that sort of thinking, where a great project is seen in the context of its connections and not as a standalone effort (http`�Jwww.campletestreets.or ). I have attached documents and included links and FHWA design guidance text here to inform future discussion and provide more than simple opinion. 7/18/2008 Page 2 of 12 A good place to start is with the guidance from NHTSA (http://www.nhtsa.dot.gov/peopie/injury/pedbimot/bik.e/bicy�le-safety/)found in their National Strategy for Advancing Bicycle Safety. The last of their five goals is Roads and Paths Will Safe-dy_Accommodate Bicyclists., but the first four have nothing to do with design. I bring this up if for no other reason than to remind us all that we can always be working on the first four and not wait for funding of the last. The attached documents from FHWA discuss a "design" bicyclist and their distinction between the type of rider who you anticipate using the facility and the sort of design accommodation you include is useful, especially were we have schools which would attract less experienced riders. The FHWA page copied below (http-//wwvv.fhwa.dot.g.ov/en_vi.ro._nment/b keped/design.h.tm ) provides a framework for evaluating competing interests in design and informs my perspective here. AARP offers a program to evaluate pedestrian facilities that may help in framing a larger discussion of how to accommodate pedestrians and I can provide that if you are interested. The larger question of bicycle pedestrian safety is addressed here (http://safety.fhwa.dot_._g_o_v_/ped bike/bikgjbsol_plan.htm ) and there is a wealth of information offered to support design that accommodates multimodal access to destinations. In my opinion, that should be our goal in all that we do in planning and land use. Bud Laumer, AICP FHWA Hoare I Feedback Environment F}IWA > HEIP > Fnvirnnment > Human > 13ic.ycle & Pcdcstrian Design Guidance Accommodating Bicycle and Pedestrian Travel: A Recommended Approach A US DOT Policy Statement Integrating Bicycling and Walking into Transportation Infrastructure Purpose Accommodating Bicycle and Pedestrian Travel: A Recommended Approach is a policy statement adopted by the United States Department of Transportation. USDOT hopes that public agencies, professional associations, advocacy groups, and others adopt this approach as a way of committing themselves to integrating bicycling and walking into the transportation mainstream. 7/18/2008 Page 3 of 12 The Design Guidance incorporates three key principles: a. a policy statement that bicycling and walking facilities will be incorporated into all transportation projects unless exceptional circumstances exist; b. an approach to achieving this policy that has already worked in State and local agencies; and c. a series of action items that a public agency, professional association, or advocacy group can take to achieve the overriding goal of improving conditions for bicycling and walking. The Policy Statement was drafted by the U.S. Department of Transportation in response to Section 1202 (b) of the Transportation Equity Act for the 21 st Century (TEA -21) with the input and assistance of public agencies, professional associations and advocacy groups. Introduction Bicycling and walking issues have grown in significance throughout the 1990s. As the new millennium dawns public agencies and public interest groups alike are striving to define the most appropriate way in which to accommodate the two modes within the overall transportation system so that those who walk or ride bicycles can safely, conveniently, and comfortably access every destination within a community. Public support and advocacy for improved conditions for bicycling and walking has created a widespread acceptance that more should be done to enhance the safety, comfort, and convenience of the nonmotorized traveler. Public opinion surveys throughout the 1990s have demonstrated strong support for increased planning, funding and implementation of shared use paths, sidewalks and on -street facilities. At the same time, public agencies have become considerably better equipped to respond to this demand. Research and practical experience in designing facilities for bicyclists and pedestrians has generated numerous national, State and local design manuals and resources. An increasing number of professional planners and engineers are familiar with this material and are applying this knowledge in towns and cities across the country. The 1990 Americans with Disabilities Act, building on an earlier law requiring curb ramps in new, altered, and existing sidewalks, added impetus to improving conditions for sidewalk users. People with disabilities rely on the pedestrian and transit infrastructure, and the links between them, for access and mobility. Congress and many State legislatures have made it considerably easier in recent years to fund nonmotorized projects and programs (for example, the Intermodal Surface Transportation Efficiency Act and the Transportation Equity Act for the 21 st Century), and a number of laws and regulations now mandate certain planning activities and design standards to guarantee the inclusion of bicyclists and pedestrians. Despite these many advances, injury and fatality numbers for bicyclists and pedestrians remain stubbornly high, levels of bicycling and walking remain frustratingly low, and most communities continue to grow in ways that make travel by means other than the private automobile quite challenging. Failure to provide an accessible pedestrian network for people with disabilities often requires the provision of costly paratransit service. Ongoing investment in the Nation's transportation infrastructure is still more likely to overlook rather than integrate bicyclists and pedestrians. In response to demands from user groups that every transportation project include a bicycle and pedestrian element, Congress asked the Federal Highway Administration (FHWA) to study various approaches to accommodating the two modes. The Transportation Equity Act for the 21 st Century (TEA -21) instructs the Secretary to work with professional groups such as AASHTO, ITE, and other interested parties to recommend policies and standards that might achieve the overall goal of fully integrating bicyclists and pedestrians into the transportation system. 7/18/2008 Page 4 of 12 TEA -21 also says that, 'Bicycle transportation facilities and pedestrian walkways shall be considered, where appropriate, in conjunction with all new construction and reconstruction of transportation projects, except where bicycle and pedestrian use are not permitted." (Section 1202) In August 1998, FHWA convened a Task Force comprising representatives from FHWA, AASHTO, ITE, bicycle and pedestrian user groups, State and local agencies, the U.S. Access Board and representatives of disability organizations to seek advice on how to proceed with developing this guidance. The Task Force reviewed existing and proposed information on the planning and technical design of facilities for bicyclists and pedestrians and concluded that these made creation of another design manual unnecessary. For example, AASHTO published a bicycle design manual in 1999 and is working on a pedestrian facility manual. The area where information and guidance was most lacking was in determining when to include designated or special facilities for bicyclists and pedestrians in transportation projects. There can also be uncertainty about the type of facility to provide, and the design elements that are required to ensure accessibility. For example, when a new suburban arterial road is planned and designed, what facilities for bicyclists and pedestrians should be provided? The task force felt that once the decision to provide a particular facility was made, the specific information on designing that facility is generally available. However, the decision on whether to provide sidewalks on neither one or both sides of the road SEC. 1202. BICYCLE TRANSPORTATION AND PEDESTRIAN WALKWAYS. (b) Design Guidance. - (1) In general. -In implementing section 217(g) of title 23, United States Code, the Secretary, in cooperation with the American Association of State Highway and Transportation Officials, the Institute of Transportation Engineers, and other interested organizations, shall develop guidance on the various approaches to accommodating bicycles and pedestrian travel. (2) Issues to be addressed. -The guidance shall address issues such as the level and nature of the demand, volume, and speed of motor vehicle traffic, safety, terrain, cost, and sight distance. (3) Recommendations. -The guidance shall include recommendations on amending and updating the policies of the American Association of State Highway and Transportation Officials relating to highway and street design standards to accommodate bicyclists and pedestrians. (4) Time period for development. -The guidance shall be developed within 18 months after the date of enactment of this Act. or a shoulder, striped bike lane, wide outside lane or separate trail for bicyclists is usually made with little guidance or help. After a second meeting with the Task Force in January 1999, FHWA agreed to develop a Policy Statement on Accommodating Bicyclists and Pedestrians in Transportation Projects to guide State and local agencies in answering these questions. Task Force members recommended against trying to create specific warrants for different facilities (warrants leave little room for engineering judgement and have often been used to avoid providing facilities for bicycling and walking). Instead, the purpose of the Policy Statement is to provide a recommended approach to the accommodation of bicyclists and pedestrians that can be adopted by State and local agencies (as well as professional societies and associations, advocacy groups, and Federal agencies) as a commitment to developing a transportation infrastructure that is safe, convenient, accessible, and attractive to motorized AND nonmotorized users alike. The Policy Statement has four elements: a. an acknowledgment of the issues associated with balancing the competing interests of motorized and nonmotorized users; b. a recommended policy approach to accommodating bicyclists and pedestrians (including people with disabilities) that can be adopted by an agency or organizations as a statement of policy to be implemented or a target to be reached in the future; c. a list of recommended actions that can be taken to implement the solutions and approaches described above; and d. further information and resources on the planning, design, operation, and maintenance of facilities for 7/18/2008 Page 5 of 12 bicyclists and pedestrians. The Challenge: Balancing Competing Interests For most of the second half of the 20th Century, the transportation, traffic engineering and highway professions in the United States were synonymous. They shared a singular purpose: building a transportation system that promoted the safety, convenience and comfort of motor vehicles. The post-war boom in car and home ownership, the growth of suburban America, the challenge of completing the Interstate System, and the continued availability of cheap gasoline all fueled the development of a transportation infrastructure focused almost exclusively on the private motor car and commercial truck. Initially, there were few constraints on the traffic engineer and highway designer. Starting at the centerline, highways were developed according to the number of motor vehicle travel lanes that were needed well into the future, as well as providing space for breakdowns. Beyond that, facilities for bicyclists and pedestrians, environmental mitigation, accessibility, community preservation, and aesthetics were at best an afterthought, often simply overlooked, and, at worst, rejected as unnecessary, costly, and regressive. Many States passed laws preventing the use of State gas tax funds on anything other than motor vehicle lanes and facilities. The resulting highway environment discourages bicycling and walking and has made the two modes more dangerous. Further, the ability of pedestrians with disabilities to travel independently and safely has been compromised, especially for those with vision impairments. Over time, the task of designing and building highways has become more complex and challenging. Traffic engineers now have to integrate accessibility, utilities, landscaping, community preservation, wetland mitigation, historic preservation, and a host of other concerns into their plans and designs - and yet they often have less space and resources within which to operate and traffic volumes continue to grow. The additional "burden" of having to find space for pedestrians and bicyclists was rejected as impossible in many communities because of space and funding constraints and a perceived lack of demand. There was also anxiety about encouraging an activity that many felt to be dangerous and fraught with liability issues. Designers continued to design from the centerline out and often simply ran out of space before bike lanes, paved shoulders, sidewalks and other "amenities" could be included. By contrast, bicycle and pedestrian user groups argue the roadway designer should design highways from the right-of-way limits in, rather than the centerline out. They advocate beginning the design of a highway with the sidewalk and/or trail, including a buffer before the paved shoulder or bike lane, and then allocating the remaining space for motor vehicles. Through this approach, walking and bicycling are positively encouraged, made safer, and included as a critical element in every transportation project rather than as an afterthought in a handful of unconnected and arbitrary locations within a community. Retrofitting the built environment often provides even more challenges than building new roads and communities: space is at a premium and there is a perception that providing better conditions for bicyclists and pedestrians will necessarily take away space or convenience from motor vehicles. During the 1990s, Congress spearheaded a movement towards a transportation system that favors people and goods over motor vehicles with passage of the Intermodal Surface Transportation Efficiency Act (1991) and the Transportation Equity Act for the 21 st Century (1998). The call for more walkable, liveable, and accessible communities, has seen bicycling and walking emerge as an "indicator species" for the health and well-being of a community. People want to live and work in places where they can safely and conveniently walk and/or bicycle and not always have to deal with worsening traffic congestion, road rage and the fight for a parking space. Vice President Gore launched a Livability Initiative in 1999 with the ironic statement that "a gallon of gas can be used up just driving to get a gallon of milk." The challenge for transportation planners, highway engineers and bicycle and pedestrian user groups, therefore, is to balance their competing interest in a limited amount of right-of-way, and to develop a 7/18/2008 Page 6 of 12 transportation infrastructure that provides access for all, a real choice of modes, and safety in equal measure for each mode of travel. This task is made more challenging by the widely divergent character of our nation's highways and byways. Traffic speeds and volumes, topography, land use, the mix of road users, and many other factors mean that a four -lane highway in rural North Carolina cannot be designed in the same way as a four -lane highway in New York City, a dirt road in Utah or an Interstate highway in Southern California. In addition, many different agencies are responsible for the development, management, and operation of the transportation system. In a recent memorandum transmitting Program Guidance on bicycle and pedestrian issues to FHWA Division Offices, the Federal Highway Administrator wrote that "We expect every transportation agency to make accommodation for bicycling and walking a routine part of their planning, design, construction, operations and maintenance activities." The Program Guidance itself makes a number of clear statements of intent: • Congress clearly intends for bicyclists and pedestrians to have safe, convenient access to the transportation system and sees every transportation improvement as an opportunity to enhance the safety and convenience of the two modes. • "Due consideration" of bicycle and pedestrian needs should include, at a minimum, a presumption that bicyclists and pedestrians will be accommodated in the design of new and improved transportation facilities. • To varying extents, bicyclists and pedestrians will be present on all highways and transportation facilities where they are permitted and it is clearly the intent of TEA -21 that all new and improved transportation facilities be planned, designed and constructed with this fact in mind. • The decision not to accommodate [bicyclists and pedestrians] should be the exception rather than the rule. There must be exceptional circumstances for denying bicycle and pedestrian access either by prohibition or by designing highways that are incompatible with safe, convenient walking and bicycling. The Program Guidance defers a suggested definition of what constitutes "exceptional circumstances" until this Policy Statement is completed. However, it does offer interim guidance that includes controlled access highways and projects where the cost of accommodating bicyclists and pedestrians is high in relation to the overall project costs and likely level of use by nonmotorized travelers. Providing access for people with disabilities is a civil rights mandate that is not subject to limitation by project costs, levels of use, or "exceptional circumstances". While the Americans with Disabillities Act doesn't require pedestrian facilities in the absence of a pedestrian route, it does require that pedestrian facilities, when newly constructed or altered, be accessible. Policy Statement 1. Bicycle and pedestrian ways shall be established in new construction and reconstruction projects in all urbanized areas unless one or more of three conditions are met: bicyclists and pedestrians are prohibited by law from using the roadway. In this instance, a greater effort may be necessary to accommodate bicyclists and pedestrians elsewhere within the right of way or within the same transportation corridor. + the cost of establishing bikeways or walkways would be excessively disproportionate to the need or probable use. Excessively disproportionate is defined as exceeding twenty percent of the cost of the larger transportation project. 7/18/2008 Page 7 of 12 • where sparsity of population or other factors indicate an absence of need. For example, the Portland Pedestrian Guide requires "all construction of new public streets" to include sidewalk improvements on both sides, unless the street is a cul-de-sac with four or fewer dwellings or the street has severe topographic or natural resource constraints. 2. In rural areas, paved shoulders should be included in all new construction and reconstruction projects on roadways used by more than 1,000 vehicles per day, as in States such as Wisconsin. Paved shoulders have safety and operational advantages for all road users in addition to providing a place for bicyclists and pedestrians to operate. Rumble strips are not recommended where shoulders are used by bicyclists unless there is a minimum clear path of four feet in which a bicycle may safely operate. 3. Sidewalks, shared use paths, street crossings (including over- and undercrossings), pedestrian signals, signs, street furniture, transit stops and facilities, and all connecting pathways shall be designed, constructed, operated and maintained so that all pedestrians, including people with disabilities, can travel safely and independently. 4. The design and development of the transportation infrastructure shall improve conditions for bicycling and walking through the following additional steps: • planning projects for the long-term. Transportation facilities are long-term investments that remain in place for many years. The design and construction of new facilities that meet the criteria in item 1) above should anticipate likely future demand for bicycling and walking facilities and not preclude the provision of future improvements. For example, a bridge that is likely to remain in place for 50 years, might be built with sufficient width for safe bicycle and pedestrian use in anticipation that facilities will be available at either end of the bridge even if that is not currently the case • addressing the need for bicyclists and pedestrians to cross corridors as well as travel along them. Even where bicyclists and pedestrians may not commonly use a particular travel corridor that is being improved or constructed, they will likely need to be able to cross that corridor safely and conveniently. Therefore, the design of intersections and interchanges shall accommodate bicyclists and pedestrians in a manner that is safe, accessible and convenient. • getting exceptions approved at a senior level. Exceptions for the non-inclusion of bikeways and walkways shall be approved by a senior manager and be documented with supporting data that indicates the basis for the decision. • designing facilities to the best currently available standards and guidelines. The design of facilities for bicyclists and pedestrians should follow design guidelines and standards that are commonly used, such as the AASHTO Guide for the Development of Bicycle Facilities, AASHTO's A Policy on Geometric Design of Highways and Streets, and the ITE Recommended Practice "Design and Safety of Pedestrian Facilities". Policy Approach "Rewrite the Manuals" Approach Manuals that are commonly used by highway designers covering roadway geometrics, roadside safety, and bridges should incorporate design information that integrates safe and convenient facilities for bicyclists and pedestrians -- including people with disabilities - into all new highway construction and reconstruction projects. In addition to incorporating detailed design information - such as the installation of safe and accessible crossing facilities for pedestrians, or intersections that are safe and convenient for bicyclists - these manuals should also 7/18/2008 Page 8 of 12 be amended to provide flexibility to the highway designer to develop facilities that are in keeping with transportation needs, accessibility, community values, and aesthetics. For example, the Portland Pedestrian Design Guide (June 1998) applies to every project that is designed and built in the city, but the Guide also notes that: "Site conditions and circumstances often make applying a specific solution difficult. The Pedestrian Design Guide should reduce the need for ad hoc decision by providing a published set of guidelines that are applicable to most situations. Throughout the guidelines, however, care has been taken to provide flexibility to the designer so she or he can tailor the standards to unique circumstances. Even when the specific guideline cannot be met, the designer should attempt to find the solution that best meets the pedestrian design principles described [on the previous page]" In the interim, these manuals may be supplemented by stand-alone bicycle and pedestrian facility manuals that provide detailed design information addressing on -street bicycle facilities, fully accessible sidewalks, crosswalks, and shared use paths, and other improvements. Examples: Florida DOT has integrated bicycle and pedestrian facility design information into its standard highway design manuals and New Jersey DOT is in the process of doing so. Many States and localities have developed their own bicycle and pedestrian facility design manuals, some of which are listed in the final section of this document. Applying Engineering Judgement to Roadway Design In rewriting manuals and developing standards for the accommodation of bicyclists and pedestrians, there is a temptation to adopt "typical sections" that are applied to roadways without regard to travel speeds, lane widths, vehicle mix, adjacent land uses, traffic volumes and other critical factors. This approach can lead to inadequate provision on major roads (e.g. a four foot bike lane or four foot sidewalk on a six lane high-speed urban arterial) and the over -design of local and neighborhood streets (e.g. striping bike lanes on low volume residential roads) , and leaves little room for engineering judgement. After adopting the policy that bicyclists and pedestrians (including people with disabilities) will be fully integrated into the transportation system, State and local governments should encourage engineering judgement in the application of the range of available treatments. For example: • Collector and arterial streets shall typically have a minimum of a four foot wide striped bicycle lane, however wider lanes are often necessary in locations with parking, curb and gutter, heavier and/or faster traffic. ■ Collector and arterial streets shall typically have a minimum of a five foot sidewalk on both sides of the street, however wider sidewalks and landscaped buffers are necessary in locations with higher pedestrian or traffic volumes, and/or higher vehicle speeds. At intersections, sidewalks may need to be wider to accommodate accessible curb ramps. • Rural arterials shall typically have a minimum of a four foot paved shoulder, however wider shoulders (or marked bike lanes) and accessible sidewalks and crosswalks are necessary within rural communities and where traffic volumes and speeds increase. This approach also allows the highway engineer to achieve the performance goal of providing safe, convenient, and comfortable travel for bicyclists and pedestrians by other means. For example, if it would be inappropriate to add width to an existing roadway to stripe a bike lane or widen a sidewalk, traffic calming measures can be employed to reduce motor vehicle speeds to levels more compatible with bicycling and walking. 7/18/2008 Page 9 of 12 Actions The United States Department of Transportation encourages States, local governments, professional associations, other government agencies and community organizations to adopt this Policy Statement as an indication of their commitment to accommodating bicyclists and pedestrians as an integral element of the transportation system. By so doing, the organization or agency should explicitly adopt one, all, or a combination of the various approaches described above AND should be committed to taking some or all of the actions listed below as appropriate for their situation. a. Define the exceptional circumstances in which facilities for bicyclists and pedestrians will NOT be required in all transportation projects. b. Adopt new manuals, or amend existing manuals, covering the geometric design of streets, the development of roadside safety facilities, and design of bridges and their approaches so that they comprehensively address the development of bicycle and pedestrian facilities as an integral element of the design of all new and reconstructed roadways. c. Adopt stand-alone bicycle and pedestrian facility design manuals as an interim step towards the adoption of new typical sections or manuals covering the design of streets and highways. d. Initiate an intensive re -tooling and re-education of transportation planners and engineers to make them conversant with the new information required to accommodate bicyclists and pedestrians. Training should be made available for, if not required of, agency traffic engineers and consultants who perform work in this field. Conclusion There is no question that conditions for bicycling and walking need to be improved in every community in the United States; it is no longer acceptable that 6,000 bicyclists and pedestrians are killed in traffic every year, that people with disabilities cannot travel without encountering barriers, and that two desirable and efficient modes of travel have been made difficult and uncomfortable. Every transportation agency has the responsibility and the opportunity to make a difference to the bicycle - friendliness and walkability of our communities. The design information to accommodate bicyclists and pedestrians is available, as is the funding. The United States Department of Transportation is committed to doing all it can to improve conditions for bicycling and walking and to make them safer ways to travel. Further Information and Resources General Design Resources A Policy on Geometric Design of Highways and Streets, 1994 (The Green Book). American Association of State Highway and Transportation Officials (AASHTO), P.O. Box 96716, Washington, DC, 20090-6716, Phone: (888) 227-4860. Highway Capacity Manual, Special Report 209, 1994. Transportation Research Board, Box 289, Washington, DC 20055, Phone: (202) 334-3214. Next Edition: FHWA Research Program project has identified changes to 7/18/2008 Page 10 of 12 HCM related to bicycle and pedestrian design. Manual on Uniform Traffic Control Devices, 1988. Federal Highway Administration (FHWA), Superintendent of Documents. P.O. Box 371954, Pittsburgh, PA 15250-7954. Next Edition: 2000, will incorporate changes to Part IX that will soon be subject of Notice of Proposed Rulemaking. Flexibility in Highway Design, 1997. FHWA. HEP 30, 400 Seventh Street SW, Washington, DC 20590. Pedestrian Facility Design Resources Design and Safety of Pedestrian Facilities, A Recommended Practice, 1998. Institute of Transportation Engineers, 525 School Street, S.W, Suite 410, Washington, DC 20024-2729, Phone: (202) 554-8050. Pedestrian Compatible Roadways -Planning and Design Guidelines, 1995. Bicycle / Pedestrian Transportation Master Plan, Bicycle and Pedestrian Advocate, New Jersey Department of Transportation, 1035 Parkway Avenue, Trenton, NJ 08625, Phone: (609) 530-4578. Improving Pedestrian Access to Transit. An Advocacy Handbook, 1998. Federal Transit Administration / WalkBoston. NTIS, 5285 Port Royal Road, Springfield, VA 22161. Planning and Implementing Pedestrian Facilities in Suburban and Developing Rural Areas, Report No. 294A, Transportation Research Board, Box 289, Washington, DC 20055, Phone: (202) 334-3214. Pedestrian Facilities Guidebook, 1997. Washington State Department of Transportation, Bicycle and Pedestrian Program, P.O. Box 47393, Olympia, WA 98504. Portland Pedestrian Design Guide, 1998. Portland Pedestrian Program, 1120 SW Fifth Ave, Room 802; Portland, OR 97210. (503) 823-7004. * Implementing Pedestrian Improvements at the Local Level, 1999. FHWA, HSR 20, 6300 Georgetown Pike, McLean, VA. * AASHTO Guide to the Development of Pedestrian Facilities, 2000. AASHTO. (currently under discussion) Bicycle Facility Design Resources Guide for the Development of Bicycle Facilities, 1999., American Association of State Highway and Transportation Officials (AASHTO), P.O. Box 96716, Washington, DC, 20090-6716, Phone: (888) 227-4860. Implementing Bicycle Improvements at the Local Level, (1998), FHWA, HSR 20, 6300 Georgetown Pike, McLean, VA. Bicycle Facility Design Standards, 1998. City of Philadelphia Streets Department, 1401 JFK Boulevard, Philadelphia, PA 19103. Selecting Roadway Design Treatments to Accommodate Bicyclists, 1993. FHWA, R&T Report Center, 9701 Philadelphia Ct, Unit Q; Lanham, MD 20706. (301) 577-1421 (fax only) North Carolina Bicycle Facilities Planning and Design Guidelines, 1994. North Carolina DOT, P.O. Box 25201, Raleigh, NC 27611. (919) 733-2804. 7/18/2008 Page 11 of 12 Bicycle Facility Planning, 1995. Pinsof & Musser. American Planning Association, Planning Advisory Service Report # 459. American Planning Association, 122 S. Michigan Ave, Suite 1600; Chicago, IL 60603. Florida Bicycle Facilities Planning and Design Manual, 1994. Florida DOT, Pedestrian and Bicycle Safety Office, 605 Suwannee Street, Tallahassee, FL 32399. Evaluation of Shared -use Facilities for Bicycles and Motor Vehicles, 1996. Florida DOT, Pedestrian and Bicycle Safety Office, 605 Suwannee Street, Tallahassee, FL 32399. Bicycle and Pedestrian Design Resources Oregon Bicycle and Pedestrian Plan, 1995. Oregon Department of Transportation, Bicycle and Pedestrian Program, Room 210, Transportation Building, Salem, OR 97310, Phone: (503) 986-3555 Improving Conditions for Bicyclists and Pedestrians, A Best Practices Report, 1998. FHWA, HEP 10, 400 Seventh Street SW, Washington, DC 20590. Traffic Calming Design Resources Traffic Calming: State of the Practice. 1999. Institute of Transportation Engineers, 525 School Street, SW, Suite 410; Washington, DC 20024. Florida Department of Transportation's Roundabout Guide. Florida Department of Transportation, 605 Suwannee St., MS -82, Tallahassee, FL 23299-0450. National Bicycling and Walking Study. Case Study # 19, Traffic Calming and Auto -Restricted Zones and other Traffic Management Techniques -Their Effects on Bicycling and Pedestrians, Federal Highway Administration (FHWA). Traffic Calming (1995), American Planning Association, 122 South Michigan Avenue, Chicago, IL 60603 Traditional Neighborhood Development Street Design Guidelines, 1997. Proposed Recommended Practice, Institute of Transportation Engineers, 525 School Street, SW, Suite 410; Washington, DC 20024. Making Streets that Work, City of Seattle, 600 Fourth Ave., 12th Floor, Seattle, WA 98104-1873, Phone: (206) 684-4000, Fax: (206) 684-5360. Traffic Control Manual for In -Street Work, 1994. Seattle Engineering Department, City of Seattle, 600 4th Avenue, Seattle, WA 98104-6967, Phone: (206) 684-5108. ADA -related Design Resources Accessible Pedestrian Signals, 1998. U.S. Access Board 1331 F Street NW, Suite 1000; Washington, DC 20004. (800) 872-2253. Accessible Rights of Way: A Design Manual, 1999. U.S. Access Board, 1331 F Street NW, Suite 1000; Washington, DC 20004. (800) 872-2253. 7/18/2008 Page 12 of 12 Designing Sidewalks and Trails for Access, Part One. 1999. FHWA, HEPH-30, 400 Seventh Street SW, Washington, DC 20590. ADA Accessibility Guidelines for Buildings and Facilities, 1998 (ADAAG). U.S. Access Board, 1331 F Street NW, Suite 1000; Washington, DC 20004. (800) 872-2253. Uniform Federal Accessibility Standards, 1984 (UFAS), available from the U.S. Access Board, 1331 F Street NW, Suite 1000; Washington, DC 20004. (800) 872-2253 Universal Access to Outdoor Recreation: A Design Guide, 1993. PLAE, Inc, MIG Communications, 1802 Fifth Street, Berkeley, CA 94710. (510) 845-0953. Recommended Street Design Guidelines for People Who Are Blind or Visually Impaired. American Council of the Blind, 1155 15th Street NW, Suite 720; Washington, DC 20005. (202) 467-5081. Trail Design Resources Trails for the 21st Century, 1993. Rails to Trails Conservancy, 1100 17th Street NW, 10th Floor, Washington DC 20036. (202) 331-9696. Greenways: A Guide to Planning, Design, and Development, 1993. The Conservation Fund. Island Press, 1718 Connecticut Ave NW, Suite 300; Washington, DC 20009. Trail Intersection Design Guidelines, 1996. Florida Department of Transportation, 605 Suwannee St., MS -82, Tallahassee, FL 23299-0450. * Indicates publication not yet available To provide Feedback, Suggestions, or Comments for this page contact Gabe Rousseau at gabe.rousseau@dot.gov_. This page last modified on March 26, 2008 )E:HWA Home I HEP Home I Feedback [Al2.IiI1 United States Department of Transportation - Federal Highway Administration 7/18/2008 -� b I o � o � c� c LM � o � LM Lm y Cd LM cp g O � Ir.44�� oho 00 Lm a � 0 LM I s g 3 = MOO b o Lm 4 - Lm O �L O �� P-4 �� a V-4 3 3 *r ut Q �*1 ce d rOM o 0 0 W X 4-1 � � G�2 •� � � �"� rel D cd g y U Cid O O Let ra 2 � 2 / 2 m 2 m 2 2 a � § R © 2 3 « $ © o � . � k ƒ ) Lft Xft ƒ § � k $ � � R � ƒ ƒ2 % $ 2 2 2 © 2 © \ C J � © 2 © � � 2 % $ 2 © 2 ®P-4 2 k' $ 8 ƒ © 2 / I co LM b La .0 C O c0 O to 4-4 o � Ca Lo CDCD LM I co oma" a� 0 y cco -14 • e o a o w �a O CrJ O C Lie� ` FOREWORD There is a need for guidance on which type of on -road bicycle facility (wide curb lane, shoulder, shared lane, or marked bicycle lane) to provide under particular roadway design and traffic operational conditions. To date, engineering judgment as well as trial and error have been used to make these decisions. This report, FHWA-RD-92-073, presents a set of tables that can be used to determine the recommended type of bicycle facility to be provided in particular roadway situations. In addition, the report presents a brief discussion of the "design user" for bicycle facilities, and presents a planning process for bicycle facilities. Five criteria were used to determine recommended bicycle facilities: traffic volume; average motor vehicle operating speed; traffic mix of automobiles, trucks, buses, and/or recreational vehicles; on -street parking; and sight distance. Values for these criteria were determined and tables were developed for urban and rural roadway sections for two groups of design users. Sufficient copies of this report are being distributed to provide a minimum of one copy to each Region and Division office and State highway agency. Additional copies for the public are available from the National Technical Information Service (NTIS), Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161. A small charge will be imposed by NTIS. Lyle Saxton, Director Office of Safety and Traffic Operations Research and Development NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trade and manufacturers' names appear in this report only because they are considered essential to the object of the document. PREFACE This manual is designed to assist transportation planners and engineers in the selection of roadway design treatments to accommodate bicycles and motor vehicles. The recommendations are based on the current state of the practice and reflect the judgment of professionals working over the past 20 years to accommodate bicycles in highway design. This process is ongoing and these recommendations will likely be refined over time. This manual is not intended to serve as a comprehensive guide to the design of highways to accommodate bicycles. The user is referred to the current edition of the American Association of State Highway and Transportation Officials' Guide to the Development of Bicycle Facilities (AASH TO Guide) for additional guidance on the design of bicycle accommodations.") The recommendations included here do address one element of design: the desirable width for various types of design treatments based on the anticipated type of bicycle users and various combinations of traffic operational factors. The recommendations reflect the first attempt to give specific guidance on the selection of roadway design treatments to accommodate bicyclists. They are based on assumptions about policy goals and about the types of bicyclists to be accommodated. Further, given that many of the conclusions and recommendations are based on professional judgment, and not on empirical research, they should be treated as "guidelines." More research, testing, and evaluation are needed to assess and refine these recommendations. (See the final report for this project for additional information on the development of these recommendations.) The project that produced this manual was originally suggested by the Transportation Research Board's Committee on Bicycling and Bicycle Facilities. The Committee forwarded a project recommendation to the Federal Highway Administration and it was selected for possible funding through the Pooled -Fund Research Program. Twelve States contributed to the fund, thus making the project possible: Delaware Ohio Florida Pennsylvania Georgia Texas Minnesota Virginia New Jersey Washington New Mexico Wisconsin This manual is organized into three major sections and an appendix. Section 1 describes the assumptions, principles, and approaches used to develop the recommendations for the selection of roadway design treatments to accommodate bicycles. This includes adapting roadway designs to accommodate bicycling on all streets and highways on which bicycle use is permitted. Section 2 is an overview of a sample planning process that can be used to identify a network of routes on which designated bicycle facilities should be provided to accommodate bicyclists of moderate ability (casual adult riders and children). Section 3 presents recommended designs and specifications for roadway designs to serve different types of bicyclists under various sets of traffic operational factors. The appendix presents a detailed discussion of the various types of bicycle facilities. TABLE OF CONTENTS Section 1. INTRODUCTION ........................................... .............................................................................1 POLICY GOAL FOR BICYCLE USE1 ........................ THE "DESIGN BICYCLIST"...........................................................................................1 DESIGNAPPROACH.....................................................................................................3 RELATEDISSUES........................................................................................................3 SUMMARY....................................................................................................................4 THE BICYCLE PLANNING PROCESS......................................................................................5 DEVELOPING A BICYCLE NETWORK PLAN , , , , , , , 5 3. DESIGN SELECTION AND SPECIFICATIONS11 TYPESTYPES OF FACILITIES................................................................................................11 DESIGNATING BICYCLE FACILITIES ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,11 PREPARING TO SELECT A FACILITY TREATMENT _ _ 12 APPENDIX: TYPES OF BICYCLE FACILITIES23 REFERENCES...................................................................................................................................... 31 LIST OF TABLES Table No. 1. Group A bicyclists, urban section, no parking....._._.__. . ............ ............................................16 2. Group A bicyclists, urban section, with parking...,......................................................................17 3. Group A bicyclists, rural section ........ 18 4. Group B/C bicyclists, urban section, no parking....,.,..................................,...............................19 5. Group B/C bicyclists, urban section, with parking.......................................................................20 6. Group B/C bicyclists, rural section....................................................................._.......................21 1. INTRODUCTION This manual is based on the answers to two key questions: 1. What is the Federal policy goal for bicycle use? 2. Who is the "design bicyclist?" POLICY GOAL FOR BICYCLE USE The two basic policy alternatives are: (1) to accommodate current bicycle use and/or (2) to increase the level of use. A review of recent policy statements by Congress, the U.S. Department of Transportation, and the Federal Highway Administration makes it clear that the Federal policy goal for bicycling is to accommodate current use and to encourage increased use, while enhancing safety.{2") Therefore, the recommendations in this manual are oriented toward meeting the needs of current and potential bicyclists using the highway system. THE "DESIGN BICYCLIST" Nearly 100 million people in the United States own bicycles. (5) The Bicycle Federation of America estimates that fewer than 5 percent would qualify as experienced or highly skilled bicyclists. Since the policy goal is to accommodate existing bicyclists and encourage increased bicycle use, there will be more novice riders than advanced bicyclists using the highway system. Therefore, any roadway treatments intended to accommodate bicycle use must address the needs of both experienced and less experienced riders. One solution to this challenge is to develop the concept of a "design cyclist' and adopt a classification system for bicycle users such as the following: • Group A --Advanced Bicyclists: These are experienced riders who can operate under most traffic conditions. They comprise the majority of the current users of collector and arterial streets and are best served by the following: - Direct access to destinations usually via the existing street and highway system. - The opportunity to operate at maximum speed with minimum delays. - Sufficient operating space on the roadway or shoulder to reduce the need for either the bicyclist or the motor vehicle operator to change position when passing. • Group B—Basic Bicyclists: These are casual or new adult and teenage riders who are less confident of their ability to operate in traffic without special provisions for bicycles. Some will develop greater skills and progress to the advanced level, but there will always be many millions of basic bicyclists. They prefer: - Comfortable access to destinations, preferably by a direct route, using either low -speed, low traffic -volume streets or designated bicycle facilities. - Well-defined separation of bicycles and motor vehicles on arterial and collector streets (bike lanes or shoulders) or separate bike paths. • Group C—Children: These are pre -teen riders whose roadway use is initially monitored by parents. Eventually they are accorded independent access to the system. They and their parents prefer the following Access to key destinations surrounding residential areas, including schools, recreation facilities, shopping, or other residential areas. Residential streets with low motor vehicle speed limits and volumes. - Well-defined separation of bicycles and motor vehicles on arterial and collector streets or separate bike paths. While other distinctions can be added, these lists support combining groups B and C bicyclists in most situations. Therefore, a "design cyclist' concept is proposed that recognizes two broad classes of bicyclists: group A riders and group B/C riders. Generally, group A bicyclists will be best served by designing all roadways to accommodate shared use by bicycles and motor vehicles. This can be accomplished by: • Establishing and enforcing speed limits to minimize speed differentials between bicycles and motor vehicles on neighborhood streets and/or by implementing "traffic -calming" strategies. • Providing wide outside lanes on collector and arterial streets built with an "urban section" (i.e., with curb and gutter). • Providing usable shoulders on highways built with a "rural section" (i.e., no curb and gutter). Generally, group B/C bicyclists will be best served by a network of neighborhood streets and designated bicycle facilities, which can be provided by: • Ensuring neighborhood streets have low speed limits through effective speed enforcement or controls and/or by implementing "traffic calming" strategies. • Providing a network of designated bicycle facilities (e.g., bike lanes, separate bike paths, or side - street bicycle routes) through the key travel corridors typically served by arterial and collector streets. • Providing usable roadway shoulders on rural highways. DESIGN APPROACH Given these two types of design bicyclists, a two-tiered approach to meeting their needs is proposed. • Group A riders will be best served by making every street "bicycle -friendly." This may be accomplished by adopting highway design standards that include wide curb lanes and paved shoulders to accommodate shared use by bicycles and motor vehicles. This approach will provide adequate space for bicycles and motor vehicles to share the roadway with minimum need for changing lanes or lane position. The desired outcome is to have sufficient space to accommodate shared use by bicycles and motor vehicles with minimum delays and maximum safety for all users. • Group B/C riders will be best served by identifying key travel corridors (typically served by arterial and collector streets) and by providing designated bicycle facilities on selected routes through these corridors. These key travel corridors can be identified through the type of planning process described in section 2 of this manual. Full implementation of this approach will result in a condition where every street on which bicycles are permitted to operate will incorporate at least the design treatments recommended for group A bicyclists. In addition, a network of routes will be enhanced by incorporating the designated bicycle facilities recommended for group B/C bicyclists. RELATED ISSUES The approach to selecting and designing roadway treatments to accommodate bicycles and motor vehicles proposed in this manual relates to other bicycle facility and program issues. Signing and Marking Bicycle Facilities Signs and pavement markings for bicycle facilities will encourage increased use. In addition to obvious traffic operations benefits, signs and pavement markings have the effect of "advertising" bicycle use. (See part IX of the Manual of Uniform Traffic Control Devices for specific details. (6)) This helps legitimize the presence of bicycles in the eyes of motorists and potential bicyclists. Also, while not discussed specifically in this manual, use of bike route signs in combination with destination information or a map can contribute to development of a network of designated bicycle routes to provide community access for group B/C bicyclists. Education/Training and Law Enforcement As with motor vehicle use, bicycle program specialists have long advocated including education/training and law enforcement activities as an integral part of encouraging and managing bicycle use. Communities must develop regular programs to educate and train adults and children on the proper use of bicycles in traffic and make bicycle -related law enforcement activities—for motorists as well as bicyclists—a routine, ongoing element of the local police department's duties. Bicycles, Motor Vehicles, and Pedestrians The highway transportation system is characterized by the interaction of three basic modes of transportation: motor vehicles (including transit services), bicycles, and walking. All decisions related to the planning, design, and implementation of highway -based transportation facilities should address the potential impact on each of these modes. Regardless of the source of funding for transportation improvements, all members of the public are entitled to use public thoroughfares by their choice of mode. Therefore, it is incumbent on transportation agencies to plan and design facilities accordingly. SUMMARY Four principles define the basic approach used for this manual: 1. Two types of design bicyclists are recognized: group A (advanced) and group B/C (basic adult and child). 2. To paraphrase the AASHTO Guide, every street and highway on which bicycles are permitted to operate is a "bicycle street" and should be designed and maintained to accommodate shared use by bicycles and motor vehicles. Thus, at a minimum, all streets should include the design treatments recommended for group A bicyclists. 3. Given the stated policy goal, a supply -driven approach of providing designated bicycle facilities to encourage increased use by group B/C riders (i.e., "if you build them they will come") is warranted. 4. Selecting design treatments to meet the needs of group B/C bicyclists involves two steps: A planning process to identify key travel corridors and/or routes along which access is important (section 2). A design decision to identify the most appropriate facility treatment for a given route or corridor (section 3). 2. THE BICYCLE PLANNING PROCESS Transportation planning is a process for making decisions about the development of transportation facilities. This includes providing accurate information about the effects proposed transportation projects will have on the community and projected users.t" Bicycle planning is no exception. However, because much of the information necessary to reach sound decisions about providing for safe, efficient bicycle use is already available as a byproduct of the normal operation of the road system, the bicycle planning process is a specific application of the overall transportation planning process. This is especially true in the case of group A bicyclists, the more experienced and proficient bicyclists that comprise about 5 percent of bicycle users in the United States. These bicyclists are able to operate on the roadway in most traffic conditions and favor the directness and right-of-way preference given to roads with a high functional classification. The planning process used to develop or improve roadways for motorists is equally valid for this type of bicyclist. There are, however, some important design features to be taken into account to best accommodate group A bicyclists, and for this reason, planners and engineers should refer to the AASHTO Guide during the planning process for streets and highways. Group A riders should be anticipated and provided for on all roadways where bicycles are not excluded by statute or regulation, regardless of functional classification. The situation is very different for group B/C bicyclists (bicyclists of average skill and experience, and children). While these bicyclists value many of the same roadway features as group A bicyclists (i.e., accessibility and directness), they also value other characteristics such as designated bicycle facilities and lower traffic volumes. Group B/C bicyclists typically prefer to ride on neighborhood streets and/or designated bicycle facilities. The location of these facilities is best determined through a planning process that seeks to determine where designated facilities are needed and the type of bicycle facilities that should be provided to accommodate and encourage group B/C bicyclists. DEVELOPING A BICYCLE NETWORK PLAN The following discussion details a planning process intended to identify a network of routes where special bicycle facility treatments should be employed to meet the needs of group B/C bicyclists. Many model planning processes could be used to select routes and design facility treatments to accommodate group B/C bicyclists. Chapter 1 of the AASHTO Guide contains several suggestions for establishing a bicycle planning program. The following process is but one example. It consists of six steps: 1. Establish performance criteria for the bicycle network. 2. Inventory the existing bicycle facility and roadway system. 3. Identify bicycle travel desire lines and corridors. 4. Evaluate and select specific route alternatives. 5. Select appropriate design treatments. 6. Evaluate the finished plan against the established performance criteria. Establish Performance Criteria for the Bicycle Network Performance criteria define the important qualitative and quantitative variables to be considered in determining the desirability and effectiveness of a bicycle facility network. These can include: • Accessibility: This is measured by the distance a bicycle facility is from a specified trip origin or destination, the ease by which this distance can be traveled by bicycle, and the extent to which all likely origins and destinations are served. Some communities (e.g., Arlington, VA) have adopted a criterion of having a bicycle facility within 1 mi (1.61 km) of every residence. More importantly, no residential area or high priority destination (school, shopping center, business center, or park) should be denied reasonable access by bicycle. • Directness: Studies have shown that most bicyclists will not use even the best bicycle facility if it greatly increases the travel distance or trip time over that provided by less desirable alternatives.(s 9) Therefore, even for group B/C bicyclists, routes should still be reasonably direct. The ratio of directness to comfort/ perceived safety involved in this tradeoff will vary depending on the characteristics of the bicycle facility (how desirable is it?), its more direct alternatives (how unpleasant are they?), and the typical user's needs (in a hurry?, business or pleasure trip?). • Continuity: The proposed network should have as few missing links as possible. If gaps exist, they should not include traffic environments that are unpleasant or threatening to group B/C riders, such as high-volume or high-speed motor vehicle traffic with narrow outside lanes. • Route Attractiveness: This can encompass such factors as separation from motor traffic, visual aesthetics, and the real or perceived threat to personal safety along the facility. • Low Conflict: The route should present few conflicts between bicyclists and motor vehicle operators. • Cost: This would include the cost to both establish and maintain the system. • Ease of Implementation: The ease or difficulty in implementating proposed changes depends on available space and existing traffic operations and patterns. Inventory Existing System Both the existing roadway system and any existing bicycle facilities should be inventoried and evaluated. The condition, location, and level of use of existing bicycle facilities should be recorded to determine if they warrant incorporation into the proposed new network or if they should be removed. If existing bicycle facilities are to be used as the nucleus of a new or expanded network, the inventory should note which improvements to the existing portions of the network may be required to bring the entire new network up to uniform design and operations standards. A simple inventory of the roadway system could be based on a map of the annual average daily traffic (AADT) counts on each road segment within a community or region. A more complex inventory could include factors such as the number of traffic lanes, the width of the outside lane, the posted speed limit or actual average operating speed, the pavement condition, and certain geometric and other factors (e.g., the frequency of commercial driveways, grades, and railroad crossings). Identify Bicycle Travel Corridors Predicting bicycle travel corridors for a community is not the same as identifying the routes that bicyclists currently use. Instead, travel corridors can be thought of as "desire lines" connecting neighborhoods that generate bicycling trips with other zones that attract a significant number of bicycling trips. For motor vehicle traffic, most peak morning trips are made between residential neighborhoods and employment centers. In the evening peak, the opposite is true. In the evening or on weekends, the pattern of trip generation is much more dispersed as people travel to shopping centers, parks, and the homes of friends or relatives. Estimating these trip flows for an entire city can be a complex, time-consuming effort requiring significant amounts of raw data and sophisticated computer models. Fortunately, transportation planning for bicycles is much simpler. Unlike traditional transportation planning that attempts to predict travel demands between future zones on as -yet -unbuilt streets and highways, bicycle planning attempts to provide for bicycle use based on existing land uses assuming that the present impediments to bicycle use are removed. These desire lines are, in fact, well represented by the traffic flow on the existing system of streets and highways. The underlying assumption is that people on bikes want to go to the same places as do people in cars (within the constraints imposed by distance), and the existing system of streets and highways reflects the existing travel demands of the community. Furthermore, most adults have a mental map of their community based on their experience as motor vehicle operators. Thus, they tend to orient themselves by the location of major streets and highways. Therefore, a good way to estimate desire lines for bicyclists and to project bicycle trips is based on the existing pattern of motor vehicle flows. The simplest way to do this is to multiply the AADT of each segment of the road system by the bicycle mode split (the percentage of all trips that are made by bicycle) for the community or region. For the first time, the 1990 census will provide bicycle mode splits for census tracts and entire communities. Mode split estimates of total trips by bicycle in American cities have ranged between 3 and 11 percent.(' 0-12) Again, it is important to note that the resulting map may not be a representation of where cyclists are now, but is instead a reflection of where bicyclists wish to go. The actual travel patterns of group B/C cyclists are heavily influenced by their perception of the bicycling environment they face. Uncomfortable or threatening bicycling conditions will cause these bicyclists to alter route choice from their most preferred alignment, choose a different travel mode, or not make the trip at all. Thus, the task of the transportation planner for bicycling is to ask, "Where are the bicyclists now?" and "Where would they be if they could go where they preferred?" Although this use of existing traffic flows is a useful overall predictor of bicyclists' desire lines, a few special situations may require adjustments to the corridor map: • Schools—especially colleges and universities—and military bases can generate a disproportionately large share of bicycle trips. This is especially true for campuses where motor vehicle parking is limited. • Parks, beaches, libraries, greenways, rivers and lakesides, scenic roads, and other recreational facilities attract a proportionately higher percentage of bicycle trips. Evaluate and Select Specific Route Alternatives The corridor identification procedure identifies desire lines for bicycle travel between various locations. The next step is to select specific routes within these corridors that can be designed or adapted to accommodate group B/C bicyclists and provide access to and from these locations. The aim is to identify the routes that best meet the performance criteria established in the first step of this planning process. Typically, this step and the selection of appropriate design treatments are highly interactive processes. The practicality of adapting a particular route to accommodate group B/C bicyclists may vary widely depending upon the type of design treatment selected. For example, a less direct route may become the best option if compara-tively few, inexpensive, and easily implemented design improvements are required. Therefore, steps 4 and 5 should be approached as an iterative loop in which both route selection and design treatment are considered together to achieve a network that is highly advantageous to the user, is affordable, has few negative impacts on neighbors and other nonusers, and can be readily implemented. In summary, the selection of a specific route alternative is a function of several factors, including: • The degree to which a specific route meets the needs of the anticipated users as opposed to other route options. • The possible cost and extent of construction required to implement the proposed bicycle facility treatment. • The comparative ease of implementing the proposed design treatment. For example, one option may entail the often unpopular decision to alter or eliminate on -street parking while another does not. • The opportunity to implement the proposed design treatment in conjunction with a planned highway construction or reconstruction project. A more inclusive list of factors to be considered in the selection of a specific route is presented in the AASHTO Guide.') Select Appropriate Design Treatments Guidelines for selecting an appropriate design treatment are presented in section 3 of this manual. In overview, the principal variables affecting the applicability of a design treatment are: • The design bicyclist. Is the proposed route projected to be used primarily by group A bicyclists, or is it intended to also serve as part of a network of routes for group B/C bicyclists? • The type of roadway project involved on the selected route. Is the roadway scheduled for construction or reconstruction, or will the incorporation of design improvements be retrofitted into existing geometrics or right-of-way widths? • Traffic operations factors. The most significant traffic operations factors for determining the appropriateness of various design treatments are: - Traffic volume. - Average motor vehicle operating speeds. - Traffic mix. On -street parking. - Sight distance. Number of intersections and entrances. Evaluate the Finished Network Plan Using the Established Performance Criteria Will the proposed network meet the criteria established at the start of the planning process? If it does not meet most of these criteria, or inadequately meets a few critical goals, either the proposal will require further work, or the performance criteria must be modified. In the latter case, the planning process as a whole should be reviewed to determine if previously discarded routes should be reconsidered. They may now be more preferred options in light of the newly modified criteria. This reality check is important. Many well -considered proposals fail when it is determined that the finished product no longer meets its established objectives. 3. DESIGN SELECTION AND SPECIFICATIONS This section provides recommendations for selecting roadway design treatments to accommodate bicycles. Specific dimensions are suggested for the width of the recommended facility type. These recommendations reflect the current state of the practice in the design of bicycle -friendly roadways. Users of this manual are encouraged to treat these recommendations as "guidelines" rather than absolute standards. TYPES OF FACILITIES Five basic types of facilities are used to accommodate bicyclists: • Shared lane: shared motor vehicle/bicycle use of a "standard" -width travel lane • Wide outside lane: an outside travel lane with a width of at least 14 ft (4.2 m). • Bike lane: a portion of the roadway designated by striping, signing, and/or pavement markings for preferential or exclusive use of bicycles. • Shoulder: a paved portion of the roadway to the right of the edge stripe designed to serve bicyclists. • Separate bike path: a facility physically separated from the roadway and intended for bicycle use. Each of these facilities is discussed in detail in the appendix. DESIGNATING BICYCLE FACILITIES An important consideration regarding the five types of facilities designs is whether or not they should be designated, by pavement markings and/or signs, as bicycle facilities. As discussed in section 1, group B/C bicyclists prefer designated facilities for bicycle use. Therefore, when bike lanes or shoulders are provided to serve group B/C riders, some designation should be included. However, the legality of bicycle use on highway shoulders may not be well defined in every State. This is due, in part, to the current language in the Uniform Vehicle Code regarding where vehicles are permitted to operate. Users of this manual are encouraged to contact their State Attorney General's office to determine the current situation regarding bicycle use on selected highway shoulders. Consideration should be given to amending some State vehicle codes to explicitly permit this widespread practice. When design treatments are provided primarily to serve group A riders, designation is optional. In some cases, it may be more desirable not to designate the facility for bicycle use. For instance, if bicycle use is permitted on the shoulder of a controlled access freeway, it is usually not appropriate to designate this roadway as a bicycle facility unless this route serves as the only link between two points. Another consideration involves minor or marginal roadway improvements for bicyclists, such as providing a narrow (less than 4 -ft [1.2-m]) shoulder. This can significantly improve riding conditions for group A bicyclists and should be considered if no better treatment is possible. However, this width is less than the minimum called for in virtually all design specifications and therefore should not be designated as a bicycle facility. Where a facility is intended to be designated as a "bicycle facility" it is essential the design conform to the State standard or AASHTO guidelines. PREPARING TO SELECT A FACILITY TREATMENT To determine the appropriate highway design treatment to accommodate bicyclists, several factors associated with the specific route or project must be assessed: 10 • What types of bicyclists is the route most likely to serve? • What type of roadway project is involved (new construction, reconstruction, or retrofit)? • What are the current and anticipated traffic operations and design characteristics of the route that will affect the choice of a bicycle design treatment? What Types of Bicyclists is the Route Most Likely to Serve? This manual takes its lead from the AASHTO Guide, which states: To varying extents, bicycles will be ridden on all highways where they are permitted. All new highways, except those where bicyclists will be legaliy prohibited, should be designed and constructed under the assumption that they will be used as a bicycle street.(') Using the concept of two broad types of design bicyclists --group A and group B/C— the recommendations included in tables 1 through 6 are keyed to the most likely type of user. All streets and highways where bicycles are permitted to operate should, at a minimum, incorporate the design treatments recommended in the tables for group A bicyclists. Where it is determined that use by group B/C bicyclists is likely, the tables recommending design treatments for group B/C should be used. The group B/C design treatments will also accommodate group A bicyclists. At a minimum, all streets and highways open to bicycle use should have roadways incorporating the design treatments recommended for group A bicyclists. Where a planning process has determined a given route is the best choice to form part of a network of routes to provide access to the community for group B/C bicyclists, the recommended design treatment appropriate to B/C riders should be implemented. New Construction and Reconstruction vs. Retrofitting The recommended design treatments in the tables are most easily implemented when new construction or reconstruction is planned. It is a relatively straightforward process to adopt the specified design treatment for bicycles at the project planning stage. When implementation involves retrofitting an existing roadway to accommodate bicycle use, the project can be more complex. Existing streets built with a curb and gutter section will often be viewed as having a fixed width and improvements will likely be limited to "moving paint," that is, restriping the existing lanes. When working with existing streets and highways, planners should investigate the opportunity to make at least minor or marginal improvements. However, where the need is to serve group B/C bicyclists, it is essential to commit the resources necessary to provide facilities that meet the recommended design treatments. Only then can routes and facilities be designated for bicyclists and provide the desired access to the community. (13) Which Traffic Operations and Design Factors Help Determine the Appropriate Design Treatment? A general consensus has ernerged among transportation planners and engineers working with bicycle facilities on the traffic operations and resign factors having the greatest effect on bicycle use.(") Six factors are most often cited; five are used to define the recommendations contained in the tables. Each of these factors is discussed below along with the ranges of values used to differentiate levels of needs. Determining these ranges was difficult; there is little in the state of the practice to go by, and there is tremendous regional variation in prevailing conditions. Therefore, it is again suggested that the tables be used as a guide and that adjustments be considered to reflect, for instance, different values for the ranges for annual average daily traffic (AADT) volume. 11 The six major factors are as follows: • Traffic volume. Higher motor vehicle traffic volumes represent greater potential risk for bicyclists and the more frequent overtaking situations are less comfortable for group B/C bicyclists unless special design treatments are provided. The recommendations contained in the tables are based on three ranges of AADT: Under 2,000 AADT. 2,000 to 10,000 AADT. Over 10,000 AADT. • Average motor vehicle operating speed. The average operating speed is more important than the posted speed limit, and better reflects local conditions. Again, motor vehicle speed can have a negative impact on risk and comfort unless mitigated by special design treatments. Four ranges of average speeds are used: - Less than 30 mi/h (less than 48.3 km/h). 30 to 40 mi/h (48.3 to 64.4 km/h). - 41 to 50 mi/h (66 to 80.5 knri Over 50 mi/h (over 80.5 km/h). • Traffic mix. The regular presence of trucks, buses, and/or recreation vehicles (i.e., approximately 30 per hour or more) can increase risk and have a negative impact on comfort for bicyclists. At high speeds, the wind blast from such vehicles can create a serious risk of falls. Even at lower operating speeds, shared lane use is less compatible. All types of bicyclists prefer extra roadway width to accommodate greater separation from such vehicles. Many bicyclists will choose a different route or not ride at all where there is a regular presence of such traffic unless they are able to remove themselves several Feet from these motor vehicles.(') The recom-mendations contained in the tables suggest different design treatments and widths depending on whether or not the volume of truck, bus, and/or recreational vehicles is likely to have a negative impact on bicycle use. • On -street parking. The presence of on -street parking increases the width needed in the adjacent travel lane or bike lane to accommodate bicycles. This is primarily a concern associated with streets and highways built with an urban section. It is addressed in the recommendations by including a separate set of tables for urban sections with on -street parking. • Sight distance. "Inadequate sight distance" relates to situations where bicycles are being overtaken by motor vehicles and where the sight distance is likely less than that needed for a motor vehicle operator to either change lane positions or slow to the bicyclist's speed. This problem is primarily associated with rural highways, although some urban streets have sight distance problems due to poor design and/or sight obstructions. The most effective response to the problem is to correct it. Providing for bicycle operation to the right of the designated motor vehicle lane (i.e., on a bike lane or shoulder) or, at speeds less than 41 mi/h (66 km/h), by adding extra width to a wide outside lane, are viable options. Number of intersections. Intersections pose special challenges to bicycle and motor vehicle operators, especially when bike lanes or separate bike paths are introduced. The AASHTO Guide and various State design manuals include general guidelines for intersection treatments. (1,14,15) While not included as a selection factor in the tables, the number and/or frequency of intersections should be considered when assessing the use of bike lanes. There is some evidence to suggest that the disruption in traffic operations associated with bike lanes is temporary. Over time, both bicyclists and motorists adapt to the new traffic patterns, learning to look for each other and effect merges prior to intersections. (16) 12 How to Use the Tables to Determine the Recommended Treatment Recommended roadway design treatments and widths to accommodate bicycles are presented in tables 1 through 6. There are separate tables for group A and group B/C bicyclists. The design treatments for group A bicyclists should be used as a guide to the minimum design for any roadway on which bicycle use is permitted. The recommended design treatments for group B/C bicyclists should be considered the desirable design for any route on which this type of bicyclist is likely to ride. There are separate tables for the two basic types of roadway sections: urban (with curb and gutter) and rural (without curb and gutter). Separate tables are provided for highways with urban sections with on - street parking and with no on -street parking. [Note: Controlled -access freeways are considered a special case and are not addressed by the tables. Several States now permit bicyclists to operate on the shoulder of some or all of their controlled -access freeways. (13) Controlled -access freeway rights of way also have been used for separate bike paths.] The tables indicate the appropriate design treatment given various sets of traffic operations and design factors. The tables do not include any specific recommenda-tions for separate bike paths. The use of separate bike paths depends on specific right-of-way conditions (e.g., very few intersections, adequate set -back) that do not exist along most highways. These conditions are most often found along parkways, river and lake shores, in park and recreation areas, on abandoned railroad rights of way, and on the right of way of some controlled -access freeways. Where such suitable conditions exist, separate bike paths can be pleasant additions to the facilities available to bicyclists. However, they cannot take the place of access to the roadway of the street and highway system. Recommendations are provided for the width of the various recommended design treatments. These recommended dimensions are considered to be "desirable widths." They should be treated as "minimum widths" unless special circumstances preclude such development. Any treatment specifically designated for bicycle use must meet the minimum design standards called for in the AASHTO Guide or the appropriate State standard. Finally, these recommendations are preliminary and should be tested and refined over time. It is anticipated that this manual will be revised to reflect the continuing evolution of the state of the practice in selecting design treatments for roadways to accommodate shared use by bicycles and motor vehicles. 14 15 16 17 18 19 20 APPENDIX: TYPES OF BICYCLE FACILITIES There are many ways in which bicycles can be accommodated on roadways and other rights of way. This section provides an overview of shared lanes, special design treatments, and other possible improvements, including European traffic -calming techniques. SHARED LANES Shared lanes are streets and highways with no special provision for bicyclists. Shared lanes typically feature 12 -ft (3.6-m) lane widths or less with no shoulders, allowing cars to safely pass bicyclists only by crossing the center line or moving into another traffic lane.0" In residential areas with low motor vehicle traffic volumes and average motor vehicle speeds of less than 30 mi/h (48.3 km/h), this should present no problem for group A riders, and will normally be adequate for group B/C bicyclists to use as well if the lane width is at least 12 ft (3.6 m). Where existing lane width is less than 12 ft (3.6 m), additional lane width or lower operating speed is called for. With higher speeds and traffic volumes, shared lanes become less attractive routes, especially to group B/C riders. As the AASHTO Guide notes, however: To varying extents bicycles will be ridden on all highways where they are permitted. All new highways, except those where bicyclists will be legally prohibited, should be designed and constructed under the assumption that they will be used by bicyclists. Bicycle safe design practices should be followed to avoid the necessity for costly subsequent improvements.' f The AASHTO Guide goes on to note other actions by which bicycle use of shared roadways—regardless of lane widths or type of user—can be improved. Bicycle -safe drainage grates, smooth pavement, bicycle -safe railroad crossings, and traffic signals that respond to bicycles are all listed as examples. Shared lanes do not usually require any special signing for bicyclists. Exceptions to this include situations when: • Specific destinations or potential alternate routes for bicyclists need to be shown. • A short gap exists between special bicycle facilities, such as between two trails, and bicyclists require signing to lead them to the next facility. 21 SPECIAL DESIGN TREATMENTS There are four general types of bicycle facilities that can improve upon shared roadways where traffic volumes or speeds make it prudent to do so. In three of the four cases, the facility allows bicyclists and motorists to operate parallel to each other in the same lane without coming too close and without motorists having to change lanes to pass the bicyclists. Wide Curb Lanes Wide curb lanes, or wide outside lanes, can be defined as right -most through traffic lanes that are substantially wider than 12 ft (3.6 m). Most practitioners agree that 14 ft (4.2 m�—usually measured from the lane stripe to the edge of the gutter pan, rather than the curb face—is the minimum width necessary to allow a bicyclist and motorist to share the same lane without coming into conflict, changing lanes, or potentially reducing the motor vehicle capacity of the lane. Where traffic speeds exceed 40 mi/h (64.4 km/h), and when annual average daily traffic exceeds 10,000, 15- or 16 -ft (4.5- or 4.8-m) lanes are considered desirable. Wide curb lanes have three widely accepted advantages. (16) They can: • Accommodate shared bicycle/motor vehicle use without reducing the roadway capacity for motor vehicle traffic. • Minimize both the real and perceived operating conflicts between bicycles and motor vehicles. • Increase the roadway capacity by the number of bicyclists capable of being accommodated. Many other benefits are claimed for wide outside lanes ranging from assisting turning vehicles in entering the roadway without encroaching into another lane to better accommodating buses and other wider vehicles. (18) Wide outside lanes require the least amount of additional maintenance of the different facilities. The sweeping effect of passing motor vehicles and routine highway maintenance is usually enough to keep the lane free of debris and in good condition for bicycling. Wide outside lanes are especially valuable for, and often favored by, group A riders who are not easily intimidated by high traffic volumes and speeds. These riders do not require a designated space in which to ride or designation of the street as a bike route. The same is not true for group B/C riders. Except on residential or low-volume streets, wide outside lanes are not generally sufficient to provide the degree of comfort and safety required by less skilled bicyclists or children and will do little to encourage them to ride Wide curb lanes will be most applicable, therefore, in urban areas on major streets where group A riders will likely be operating. If no alternative route exists for group B/C riders, a bike lane or shoulder should typically be used. The Florida Department of Transportation has recently amended its policy of always providing wide curb lanes on State highways in urban areas to that of providing bike lanes. (19) Bike Lanes The AASHTO Guide defines a bicycle lane as: A portion of the roadway which has been designated by striping, signing and pavement markings for the preferential or exclusive use of bicyclists.' Bike lanes are sometimes referred to as Class II Bikeways, according to the classification system still used by the California Department of Transportation (Caltrans).(") 22 Both Caltrans and the AASHTO Guide agree that bike lanes should always be one-way facilities carrying traffic in the same direction asadjacent motor vehicle traffic, and that they should not be placed between parking spaces and the curb.(''19) The recommended width for a bike lane is 5 ft (1.5 m), at least 4 ft (1.2 m) of which should lay to the left of the gutter pan seam. (However, the Florida DOT is currently experimenting with slightly narrower undesignated lanes in some urban areas.) Field studies carried out as part of the research for this manual indicate that bike lanes have a strong channelizing effect on motor vehicles and bicycles. (16) The Caltrans Highway Design Manual describes this effect very clearly: Bike lane stripes are intended to promote the orderly flow of traffic, by establishing specific lines of demarcation between areas reserved for bicycles and lanes to be occupied by motor vehicles. This effect is supported by bike lane signs and pavement markings. Bike lane stripes can increase bicyclists' confidence that motorists will not stray into their path of travel if they remain in the bike lane. Likewise, with more certainty as to where bicyclists will be, passing motorists are less apt to swerve towards opposing traffic in making certain they will not hit bicyclists!") The impact of marked bike lanes is particularly important for group B/C riders. The lanes offer a designated and visible space for bicyclists and can be a significant factor in route choice. Motorists also benefit from the channelizing effect of bike lanes. Use of bike lanes does require an additional commitment to maintenance. Bike lanes must be kept free of debris and loose gravel to remain useful and safe, which may require routine sweeping beyond that necessary for streets with no bike lanes. As motor vehicles are not allowed in the lanes, they cannot sweep the debris aside as they do in ordinary (12 -ft [3.6-m]) traffic lanes. The bike lane stripes themselves must be maintained on a regular basis. Other important issues include the presence of on -street parking and the number and complexity of intersections. Parking movements and car doors opening have the potential to cause crashes, so bike lanes should be designed to minimize these conflicts. For example, on streets with parking lanes: • Bike lanes should be at least 5 ft (1.5 m) wide. • Bike lanes should be placed between the outer motor vehicle lane and the parking lane. • Both sides of the bike lane should be marked. The righthand marking will demarcate where motor vehicles should park and will allow sufficient clearance for a bicyclist to avoid car doors that are opening. • Bike lanes are not advisable where angled parking is present. Bicycle lanes can complicate turning movements at intersections if they encourage bicyclists to keep right and motorists to keep left, regardless of their turning intentions. Some jurisdictions have addressed this issue by ending bike lanes in advance of intersections, or by striping the lane with a broken, rather then a solid, white line in advance of the intersection to encourage merging. (14,15) It is the conclusion of the current study that bike lanes do have wide applicability, especially for group B/C riders in urban areas. When average daily traffic flows exceed 10,000 or average motor vehicle speeds exceed 30 mi/h (48.3 km/h), 5 -ft (1.5-m) bike lanes will attract and serve group B/C riders better than wide outside lanes or other design treatments. Shoulders AASHTO's "Policy on the Geometric Design of Highways and Streets" defines a shoulder as: 23 ... the portion of the roadway contiguous with the traveled way for accommodation of stopped vehicles, for emergency use and for lateral support of the subbase, base and surface courses.(21) Shoulders are also useful as places for bicyclists to ride. AASHTO and many States explicitly recognize that adding or improving shoulders is often the best way to accommodate bicyclists—especially in rural areas!`" Shoulders should be a minimum of 4 ft (1.2 m) wide when designed to accommodate bicycle travel. While group A (and even some group B/C cyclists) will benefit from shoulder widths as narrow as 1 or 2 ft (0.3 to 0.6 m), these facilities should not be signed for bicyclists if they fail to meet prevailing State and/or AASHTO guidelines. As traffic speeds increase, traffic mix includes heavier vehicles and trucks, and traffic volumes rise, added width is desirable. For example, once vehicle speeds exceed 40 mi/h (64.4 km/h) and AADT is 2,000 or more, shoulder widths should usually be increased to 6 ft (1.8 m). In urban areas, wide curb lanes are usually preferable to shoulders for group A riders and bike lanes are usually preferable for group B/C riders. One exception will be on high-speed urban arterials (more than 50 mi/h [80 km/h]) where 6 -ft (1.8-m) shoulders will serve group A riders better than wide curb lanes. Bike lanes, if used along these routes, should also be at least 6 ft (1.8 m) wide. Bicyclists will use shoulders where they are paved and maintained to the same surface standard as regular travel lanes. Where shoulders are designated as bike facilities, it is essential to keep them in good repair and free of debris, which often means a regular inspection and maintenance program. Other surface irregularities, such as rumble strips, textured paving, and raised lane markers and reflectors, should be avoided on routes explicitly intended for bicyclists as they can cause falls or force bicyclists to ride in the traffic lane. Where the use of rumble strips is necessary, they should be located so as to leave a portion of the shoulder free for bicyclists. Some State vehicle codes may, under a strict interpretation, prohibit or restrict the use of shoulders by all vehicles, including bicycles. Other States require bicyclists to use shoulders where they exist and are of an adequate standard for riding. (16) Additional research may be required to determine the exact legal status of bicyclists using shoulders in a particular State. Comparable differences exist regarding the treatment of bicycles on controlled -access freeway or Interstate highway shoulders. Eighteen western States allow bicyclists to use some or all of such shoulders (except in urbanized areas), whereas in all eastern States except New Jersey, such use is currently prohibited. Additional attention should be given to accommodating bicycle use on controlled - access freeway shoulders where such use provides the only crossing of a river, lake, freeway, or other barrier. Separate Bike Paths The AASHTO Guide defines a bicycle path or bike path as: A bikeway physically separated from motorized vehicular traffic by an open space or barrier and either within the highway right-of-way or within an independent right -of -way -0) Separate bike paths are also known as Class I Bikeways, according to the classifica-tion used by the Caltrans. They also may be referred to as "multi -use trails" or "green -ways," even though they are slightly different facilities. (20) A trail typically runs along an independent right of way such as an abandoned railroad corridor, and a greenway is a park -type corridor of land that may or may not incorporate a trail within its boundaries. 24 Two-way bike paths should be at least 10 ft (3 m) wide. Where possible, especially if bicycle or pedestrian traffic is expected to be high, paths should be a minimum of 12 ft (3.6 m) wide. Given the variety of users of most bike paths, 8 -ft (2.4 m) widths will generally not be adequate. One-way bike paths have a limited application as without strict enforcement, they will be used as two-way facilities. If they are provided, however, they should be at least 5 ft (1.5 m) wide. Bike paths are a valuable addition to the highway system and to the range of facilities available to planners and engineers seeking to improve conditions for all categories of bicyclist. They can serve both a transportation and recreation function and have proven to be significant generators of bicycle use. Both groups A and B/C riders (as well as other nonmotorized users) can benefit from the absence of motor vehicle traffic on these paths. Bike paths are not inherently more dangerous than other bicycle facilities if they are well designed, thoughtfully applied, and adequately maintained. For example, paths should not have their continuity destroyed by frequent motor vehicle cross flows and intersections with highways. These increase potential conflicts and are likely to make the route less popular with riders seeking to maintain momentum, particularly group A. Where adequate, uninterrupted right of way is available, separate bike paths can be used to good effect in providing long, continuous routes for commuting or recreation trips, access to destinations not otherwise available to bicyclists, and as cut-throughs between buildings and other breaks in the street network. OTHER POSSIBLE IMPROVEMENTS Sidewalks The AASHTO Guide states quite simply that "Sidewalks are generally not acceptable for bicycling."(1) This statement is qualified by a recognition that in a few, specific instances, such as on long, narrow bridges, the designation of a sidewalk as a bicycle facility may be beneficial. Many States share this view. Sidewalks are generally inappropriate for use by adults because they put the adult bicyclist in conflict with motorists using driveways, and with pedestrians, utility poles and signposts. Also, the cyclist is generally not visible or noticed by the motorist so that the cyclist suddenly emerges at intersections, surprising the motorist and creating a hazardous condition. 5) Traffic Calming Still relatively new to the United States, widespread neighborhood traffic calming aims to reduce the dominance and speed of motor vehicles. Measures employed to achieve this include physical alterations to the horizontal and vertical alignment of the road and changes in priority. For example, speed humps, diverters, traffic throttles, traffic islands, sidewalk extensions, and mini -traffic circles have all been utilized to calm or tame traffic. Low speed zones --for example, 20 mi/h (32.2 km/h) or lower—are often introduced along with a package of these physical changes. (23) Traffic calming was started as a means to reduce the impact of traffic in residential neighborhoods and around schools. During the 1980's, the principles of traffic calming were extended and are now being applied to major roads in urban areas. Four key benefits have been attributed to traffic calming: • An average one-third reduction in road accidents. • A greater feeling of security, particularly among vulnerable road users such as bicyclists and pedestrians. • Reclamation of roadway space for nontraffic activities such as play and social interaction. • Environmental improvements through landscaping and a reduction in the intrusive presence of motor vehicles. (23) Much of the pioneering work in this field has been in Europe, particularly Germany and the Netherlands. In areas of traffic calming in both countries it is rare to see special facilities for bicyclists since many of the benefits of traffic calming—slower vehicle speeds, better driver discipline, less traffic, environmental improvement —directly benefit bicyclists, especially group B/C riders. Nevertheless, according to the Cyclists Touring Club in the United Kingdom: Ill -designed traffic -calming schemes can inconvenience or even endanger cyclists. Balanced on two wheels and without the benefit of suspension, cyclists are particularly susceptible to changes in surface height and texture or may be put at risk by poorly -considered road narrowing. (23) Careful design of traffic -calming schemes can overcome these potential pitfalls and ensure that the benefits of such work encourage bicycling and make the activity safer. (23.24) Some U.S. cities, such as Seattle, have developed traffic -calming techniques similar to those found in European countries, but not to the same geographic extent. Other Roadway Improvements It is possible to marginally improve some roadways for bicyclists—particularly group A riders—by providing as little as 2 ft (0.6 m) of usable riding surface to the right of the edge stripe. While this will not meet the design specifications necessary for a designated bicycle facility, it can provide an improved operating environment for both bicyclists and motor vehicles and will reduce the impact of bicycles on highway capacity. This and other marginal roadway improvements should be considered when the opportunity arises and there is no other option—such as wider shoulders, a bike lane, or wide curb lane—because of lack of space. 26 REFERENCES 1. Guide for the Development of Bicycle Facilities, American Association of State Highway and Transportation Officials (AASHTO), Washington, DC, 1991. 2. "The Intermodal Surface Transportation Efficiency Act of 1991." PL 102-240, Dec. 18, 1991. 3. Moving America: New Directions, New Opportunities, U.S. Department of Transportation, Washington, DC, Feb. 1990. 4. "Policy on Bicycle and Pedestrian Projects," Federal Highway Administration Memorandum, Washington, DC, May 7, 1991. 5. Bicycling Reference Book, 1992-93, Bicycle Institute of America, Washington, DC, May 1992. 6. Manual of Uniform Traffic Control Devices, U.S. Department of Transportation, Federal Highway Administration, Washington, DC, 1988. 7. Graber and Hoel, Traffic and Highway Engineering, West Publishing, St. Paul, MN, 1988. 8. Kroll and Sommer, "Bicyclists' Response to Urban Bikeways," Journal of the American Institute of Planners, Vol. 43, No. 1, Jan. 1976. 9. Evaluation by Experienced Riders of a New Bicycle Lane in an Established Bikeway System, Transportation Research Record 683, Transportation Research Board, Washington, DC, 1978. 10. Newman and Kenworthy, Cities and Automobile Dependence: An International Sourcebook, Gower Publishing, Aldershot, United Kingdom, 1989. 11. Alternatives to the Automobile: Transport for Livable Cities, Worldwatch Paper No. 98, Worldwatch Institute, Washington, DC, Oct. 1990. 12. Bicycle Use in Medium -Sized Cities, Lane Council of Governments, based on 1980 census data, Eugene, OR, 1983. 13. Wm. C. Wilkinson, Highway Route Designation Criteria for Bicycle Routes, FHWA-RD-86-???, Federal Highway Administration, Washington, DC, 1986. 14. Arizona Bicycle Facilities Planning and Design Guidelines, Arizona Bicycle Task Force, Tucson, AZ, Nov. 1988. 15. Bicycle Master Plan, Oregon Department of Transportation, Salem, OR, May 1988. 16. Wm. C. Wilkinson et al., The Effect of Bicycle Accommodations on Bicycle/Motor Vehicle Safety and Traffic Operations, Final Report, FHWA-RD-92-069, Federal Highway Administration, Washington, DC, November 1992. 17. Highway Capacity Manual, Transportation Research Board, Washington, DC, 1985. 18. "Policy for Incorporation of Bicycle Facilities in Design," Florida Department of Transportation Memorandum, Tallahassee, FL, March 1984. 19. Personal communication with Dan Burden, Florida State Bicycle and Pedestrian Coordinator, May 11, 1992. 20. California Highway Design Manual, California Department of Transportation, Sacramento, CA, 1987. 21. A Policy on Geometric Design of Highways and Streets, AASHTO, Washington, DC, 1990. 22. 'Paved Shoulders," Virginia Department of Transportation Memorandum, Richmond, VA, March 26, 1992. 23. Cyclists and Traffic Calming, Cyclists Touring Club (UK), Godalming, United Kingdom, 1991. 24. Rodney Tolley, Traffic Calming in Residential Areas, Brefi Press, Dyfed, United Kingdom, 1991. 28