Loading...
HomeMy WebLinkAboutZ-4824 ApplicationJ ATRAFFIC IMPACT STUDY FOR A PROPOSED MIXED USE DEVELOPMENT LITTLE ROCK, ARKANSAS PREPARED FOR CARTER & ASSOCIATES MARCH 1987 rhe !! ENGINEERS ■ PLANNERS 000 Group A TRAFFIC IMPACT STUDY FOR PROPOSED MIXED USE DEVELOPMENT AT SHACKLEFORD ROAD/I-430 LITTLE ROCK, ARKANSAS Prepared for: CARTER AND ASSOCIATES Prepared by: THE RBA GROUP MARCH 1987 TNF AAA rZOMID i TABLE OF CONTENTS Section Page I. SUMMARY OF CONCLUSIONS AND RECOMMENDATIONS 1 II. INTRODUCTION 2 Scope of the Traffic Analysis 2 Study Area 2 III. EXISTING CONDITIONS 4 Shackleford Road 4 36th Street 4 I-430 5 Existing Traffic Volumes 5 Existing Traffic Control Devices 5 Existing Level of Service 5 IV. PROPOSED DEVELOPMENT 9 Trip Generation 9 Market Area Distribution 13 Generated and Existing Traffic 15 V. TRAFFIC IMPACTS OF THE DEVELOPMENT 18 TUC DAA GDAIID it LIST OF FIGURES Figure Page 1 SITE LOCATION MAP 3 2 EXISTING A.M. PEAK HOUR TRAFFIC VOLUMES 6 3 EXISTING P.M. PEAK HOUR TRAFFIC VOLUMES 7 4 GENERATED TRAFFIC LEVELS - A.M. PEAK HOUR 11 5 GENERATED TRAFFIC LEVELS - P.M. PEAK HOUR 12 6 MARKET AREA DISTRIBUTION 14 7 FUTURE A.M. PEAK HOUR TRAFFIC VOLUMES 16 8 FUTURE P.M. PEAK HOUR TRAFFIC VOLUMES 17 9 RECOMMENDED ACCESS PLAN 22 LIST OF TABLES Table 1 INTERSECTION CAPACITY ANALYSIS - EXISTING 8 CONDITIONS 2 TRIP GENERATION - A.M. PEAK HOUR 10 3 TRIP GENERATION - P.M. PEAK HOUR 10 4 DISTRIBUTION OF TRIPS - A.M. AND P.M. PEAK HOURS 15 5 LEVEL OF SERVICE CRITERIA FOR SIGNALIZED 18 INTERSECTIONS E RBA GROUP -1- I. SUMMARY OF CONCLUSIONS AND RECOMMENDATIONS The following is a summary of the findings of this impact study. The proposed development consist of the following five individual developments: 1. Retail a. Cinema - 8 screens, 25,600 sq.ft. b. Anchor Store - 42,000 sq.ft. c. Anchor Store - 29,450 sq.ft. d. Shops - 63,200 sq.ft. 2. Office - 150,000 sq.ft. 3. Restaurant - 6,000 sq.ft. - Commercial Site 4. Drive-in Bank - 3 Windows - 5,000 sq.ft. Commercial Site 5. Hotel - 250 Room - 100,000 sq.ft. ° The traffic expected to be generated by this development is 593 trips inbound and 233 trips outbound during the a.m. peak hour, and 744 trips inbound and 990 outbound trips during the p.m. peak hour. The primary traffic impacts are expected to occur at the intersection of Shackleford Road and I-430 Interchange. Traffic signals are needed at both ramp terminals in order to provide acceptable operations under the existing conditions. The ramp terminals will continue to operate at an acceptable level of service with the proposed development in place. TUC DRA POA11P -2 - II. INTRODUCTION This report contains a traffic impact study conducted for Carter and Associates. The study was conducted to evaluate the impacts expected to result from the traffic generated by a proposed mixed use development adjacent to Shackleford Road at I-430 in Little Rock, Arkansas. The site location is shown in Figure 1. The proposed development includes retail, office, restaurant, and hotel uses. Scope of the Traffic Analysis The scope of this analysis contains four elements: 1) an evaluation of the existing road network, including the amount of existing traffic on that network; 2) the projection of a.m. and p.m. peak hour traffic generated by the development and the distribution and assignment of that traffic to the road network; 3) the evaluation of the impact of the additional traffic on the existing road network and future improvements; and 4) recommendations for access to the project and improvements required to provide an adequate level of service to the project. Study Area The study area includes the site and portions of the surrounding road system, including Shackleford Road, 36th Street, and Interstate 430. The primary traffic impacts of the development are expected to occur at the intersection of Shackleford Road and Interstate 430 ramp exits. THE RRA GROUP SITE INt-si HAM MILLS FREEWAY W 12TH OC co w W O > 36TH ST, SITE LOCATION, MAP I FIGURE 1 I IME O LL Lu J NI � 2 SITE INt-si HAM MILLS FREEWAY W 12TH OC co w W O > 36TH ST, SITE LOCATION, MAP I FIGURE 1 -4 - III. EXISTING CONDITIONS The following briefly describes the existing roadways in the vicinity of the proposed development. The main roads relevant to this site were identified as: Shackleford Road, 36th Street, and Interstate 430. The inventory of existing conditions includes the geometrics of the roadways, the existing travel patterns, and the operational characteristics of the roadways with special attention given to traffic control. Shackleford Road Shackleford Road is a two-lane roadway in front of the site that provides a connector to I-430. The intersection of Shackleford Road and I-430 interchange has a stop sign control. Shackleford Road intersects southbound with 36th Street. North of I-430, Shackleford Road expands from two lanes to four lanes for about a mile and half. In the northwest quadrant of Shackleford and I-430 there is a suburban office complex. There is extensive office and commercial development north of Kanis Road. Thirty-sixth Street is a two-lane roadway intersecting with Shackleford Road. This intersection is controlled by a stop sign. This area has some residential development nearby, but the area is primarily undeveloped. TNF RRA GRMJP -5- I-430 I-430 is part of the network of Interstate highways forming a ring system around Little Rock. I-430 is the north/south portion on the west side of the Little Rock metropolitan area. It currently has a four -lane section. Existing Traffic Volumes The RBA Group subcontracted with Engineering Management Consultants, Inc. to conduct traffic volume counts at Shackleford and 36th Street and Shackleford and the I-430 ramps. These counts were conducted for the a.m. and p.m. peak periods in February, 1987. The existing turning movement volumes are shown in Figures 2 and 3. Existing Traffic Control Devices All intersections in the study area are stop sign controlled with Shackleford Road acting as the main road. Existing Level of Service Level of service is a measure of delay and congestion at an intersection. The level of service concept is explained in detail in Section V of this report. The existing traffic at the intersections of 36th Street and Shackleford presently operates at a level of service "A11 for all approaches for the a.m. and p.m. peak hour. TUC DHA l:Df1110 The following are the existing traffic analysis at the intersection of Shackleford Road and I-430 interchange. All approaches at the northernmost intersection of Shackleford Road and I-430 are operating at an acceptable level of service with the exception of westbound traffic turning onto I-430, which operates at a level of service "D" for the a.m. peak hours and a level of service 'IF" for the p.m. peak hours. All approaches at the southernmost intersection of Shackleford and I-430 are operating at an acceptable level of service for the a.m. peak hours; the eastbound traffic turning onto I-430 operates at a level of service 'IF" for the p.m. peak hours. Table 1 illustrates the level of service for the existing capacity analysis. Table 1: INTERSECTION CAPACITY ANALYSIS - EXISTING CONDITIONS A. M. P.M. Intersection Peak Hour Peak Hour Shackleford Road and I-430 D F Northern Intersection (westbound) Shackleford Road and I-430 C F Southern Intersection (eastbound) Shackleford Road and 36th Street A A All Approaches TMF ORA rZOMID -9 - IV. PROPOSED DEVELOPMENT The proposed development is comprised of five different individual developments. The development will take place adjacent to Shackleford Road and I-430 in the City of Little Rock, Arkansas. Trip Generation In order to determine the future traffic impacts of the proposed development it is necessary to estimate the extent of trips that will be generated by the planned development. The procedure for projecting trip generation is taken from the Trip Generation Manual published by the Institute of Transportation Engineers. This manual has a compilation of generation rates that are determined by research across the United States. The estimates of trips generated by the site is found by multiplying the square feet of leaseable space, or number of units for residential, by a standard generation factor. Table 2 summarizes the a.m, peak hour traffic generated by the development site. The p.m. peak hour traffic generation is shown in Table 3. Figures 4 and 5 illustrate the traffic generated by this proposed development. TUC BRA COMID -10 - Table 2: TRIP GENERATION - A.M. PEAK HOUR Table 3: TRIP GENERATION - P.M. PEAK HOUR A.M. Rate A.M. Trips Land Use Site Amount Enter Exit Enter Exit Retail 134,650 sq.ft. .90 .80 121 108 Cinema (25,600 sf) 8 screens 0.00 0.00 0 0 Office 150,000 sq.ft. 1.87 .22 281 33 Restaurant 6,000 sq.ft. 7.60 3.20 46 19 Bank* 3 Windows - - - - Hotel 250 Rooms .58 .29 145 73 Total 593 233 * - It is assumed that during a.m. peak hours this development will not open. Table 3: TRIP GENERATION - P.M. PEAK HOUR Total 744 990 ,TMF RRA r.Rn11P P.M. Rate P.M. Trips Land Use Site Amount Enter Exit Enter Exit Retail 134,650 sq.ft. 2.90 3.10 390 417 Cinema (25,600 sf) 8 screens 9.90 14.20 79 114 Office 150,000 sq.ft. .44 1.76 66 264 Restaurant 6,000 sq.ft. 9.90 4.00 59 24 Bank (5,000 ft.) 3 Windows 20.00 26.00 60 78 Hotel 250 Rooms .36 .37 90 93 Total 744 990 ,TMF RRA r.Rn11P -13 - Market Area Distribution After the extent of the trip generation is determined, it is then determined where the trips are coming from and going to. Trips generated by commercial activity is related to the distribution of population in the vicinity of the development. The market distribution of population in the vicinity of the development was determined by using census data. The resulting distribution is illustrated in Figure 6. The boundaries of each sector in the distribution was established so that each sector corresponds to a logical route of access to and from the site. This distribution of population can be used to determine the origin and destinations of trips generated by the commercial activity. ~ruc ORA rOMID .I E:i3 SIDE k V 16 MARKET AREA DISTRIBUTION IL S. FREEWAY IFIGURE 6 -15 - Generated and Existin Traffic To insure a satisfactory analysis of the traffic expected from the development, the generated traffic volumes were added to the existing traffic volumes in order to determine future traffic conditions. Figures 7 and 8 show the future traffic volumes for a.m. and p.m. peak hours. Table 4 shows the distribution rates for each direction from the site for the a.m. and p.m. peak. Also shown are the number of trips which will enter and exit the development in the a.m. and p.m. peak hour. These rates were used to distribute future trips to and from the site. Table 4: DISTRIBUTION OF TRIPS - A.M. AND P.M. PEAK HOURS P.M. Sector 1 8%) #2 5%) f3 (12%) #4 (50%) #5 (15%) Development In Out In Out In Out In Out In Out 1 63 67 17 19 42 45 172 186 52 56 2 12 48 3 13 8 32 33 132 10 40 3 18 7 5 2 12 5 50 20 15 6 4 11 14 3 4 7 9 30 39 9 12 5 16 17 5 5 11 11 45 47 14 14 * - It is assumed that this development will not open until after the a.m. peak hours. Source: The RBA Group TNF RRA AR(LIP A. M. Sector #1 (18%) #2 (5%) #3 12%) #4 50%) #5 (15%) Development In Out In Out In Out Tn Out In Out 1 19 17 5 14 13 12 54 38 16 14 2 51 6 14 2 34 4 139 17 42 5 3 14 6 4 2 9 4 38 17 11 5 4* 5 26 13 7 4 17 9 72 37 22 11 P.M. Sector 1 8%) #2 5%) f3 (12%) #4 (50%) #5 (15%) Development In Out In Out In Out In Out In Out 1 63 67 17 19 42 45 172 186 52 56 2 12 48 3 13 8 32 33 132 10 40 3 18 7 5 2 12 5 50 20 15 6 4 11 14 3 4 7 9 30 39 9 12 5 16 17 5 5 11 11 45 47 14 14 * - It is assumed that this development will not open until after the a.m. peak hours. Source: The RBA Group TNF RRA AR(LIP -18- V. TRAFFIC IMPACTS OF THE DEVELOPMENT This section is to describe the analysis of the expected traffic conditions and to make recommendations for measures which may be required to accommodate existing and generated travel demands. Intersection capacity analyses were performed for both existing and generated traffic volumes. The procedure used to perform capacity analysis is the methodology outlined in the 1985 Highway Capacity Manual (HCM) published by the Transportation Research Board. This methodology allows the analyst to determine a "level of service" (LOS) which is a description of the acceptability of the intersection operational characteristics. The levels of service are described in terms of stopped vehicle delay experienced by the intersection users. Levels of service are expressed in letters "A" through "F", where "A" implies little or no delay and "F" is a delay over 60 seconds per vehicle. These levels are as shown in Table 5. Table 5: LEVEL OF SERVICE CRITERIA FOR SIGNALIZED INTERSECTIONS Level of Service Stopped Delay Per Vehicle (sec.) A < 5.1 B 5.1 to 15.0 C 15.1 to 25.0 D 25.1 to 40.0 E 40.1 to 60.0 F > 60.0 ource: 1985 Highway Capacity Manual TUC DRIA 9_011110 -19 - An analysis was made using future traffic volumes with existing geometrics the results were: At the intersection of 36th Street and Shackleford the level of service for the a.m. peak hour is "A" for all approaches. The level of service for the p.m. peak hour is "A" for all approaches except the eastbound, which is "E". Therefore, at this intersection the existing geometrics can accommodate future levels of traffic with the present stop sign control. With the present geometrics and a stop sign control the northernmost intersection of Shackleford Road and I-430 interchange level of service for the a.m. peak hour resulted in "C" for the westbound left turns. The p.m. peak hour level of service is "F" for the westbound left turns. The southernmost intersection at Shackleford Road and I-430 interchange level of service for the a.m. peak hour is "D" for the eastbound ramp left turns. The level of service for the p.m. peak hour is "F" for the eastbound ramp left turns. Both intersections will require signals; which is justified with the existing geometrics and existing traffic volumes. With signalization the resulting future level of service would be as follows: At the northernmost intersection of Shackleford Road and I-430 interchange for the a.m. peak hour the level of service will be "C", and for the p.m. peak hour the level of service will be "D". At the southernmost intersection of Shackleford Road and I-430 interchange for ruc aae ranua -20 - the a.m. peak hour the level of service will be "B", and the p.m. peak hour level of service will be "D". Table 6 illustrates the future level of service. Table 6: INTERSECTION CAPACITY ANALYSIS - FUTURE CONDITIONS Intersection A. M. P.M. Peak Hour Peak Hour Shackleford Road and I-430 C D Northern Intersection (westbound) Shackleford Road and I-430 B D Southern Intersection (eastbound) Shackleford Road and 36th Street A A Shackleford Road and Site Driveway B C The site driveway onto Shackleford Road should be located at least 800' south of the northeastbound ramp intersection to allow for signalization of both ramps, and the site driveway. The driveway location must also be placed so that sufficient stopping sight distance may be maintained from both approaches on Shackleford Road until traffic signal warrants are met and a signal is installed. Preliminary studies indicate that a driveway located 850' south of the interchange will provide sufficient stopping sight distance. It is recommended that the four lane section of Shackleford Road should be extended through the site driveway. A 100' left turn lane on northbound Shackleford Road should be included. The site driveway should have a dual left turn lane and a right turn lane exiting. TWF BAA naniap -21 - The entrance side of the driveway should have two lanes. It is anticipated that a median will be incorporated in the driveway design. Careful consideration must be taken to locate the access so that acceptable stopping sight distance standards can be maintained due to the profile of Shackleford Road. Several alternative solutions to this problem exist including (1) posting a 25 mph speed limit on Shackleford Road; (2) lowering the grade on Shackleford Road; (3) installation of a traffic signal at the proposed driveway on Shackleford Road; (4) relocating the proposed driveway either north or south on the vertical tangents; or (5) a combination of the above. Due to the preliminary nature of the design at this point, it is not possible to specify a precise solution. It is obvious that the consultants and the developer are aware of the problem and will take corrective actions during the design phases of the project. The recommended access plan is shown in Figure 9. The resulting level of service for the site driveway is "B" in the a.m. peak hour and level of service "C" in the p.m. peak hour assuming the recommended plan. TWF wwe raniia CITY OF LIT 1 -ROCK N0. OFFICE OF COMPROE'NSIVE PLANNING FILING FEES Li tt1 e,RJ k% Ark. Rezoning Application • L. •'Y•1 • .'Y, V �1 R�� i t• • �;yjL ' r �4sr Board of Adjustment Application. Preliminary Plat . . . . . . . . . . . . . . . . $ Final Plat . . . . . . . . . . . . . . . . $ Street Name Signs: No. Signs At Ea. . $ L2 TOTAL $ �. t L Mai 3 By: File No.: Address: Applicant: f.