HomeMy WebLinkAboutMarkham road diet reportMarkham St. near Stifft's Station; Feasibility of Road -Diet Implementation
to Include Bike Lanes
Markham St. is classified as a Minor Arterial on the City Master Street Plan. Little Rock's Bicycle
community has been requesting the City to implement a road -diet on Markham between UAMS Campus
and State Capitol, so that bike lanes may be included on this section. Below are staff findings and
recommendations.
Present Conditions:
Markham at this location is a 4 -lane section and the width of roadway varies from 41 ft. to 43 ft. The
section between Kavanaugh and Pine has several vertical curves that affect a driver's line of sight.
Between Thayer and Barton, there is no shoulder on the south side of Markham because of the steep
vertical slope that begins right at the road -edge. On the north -side, there are several power poles right
next to the curb with less than a foot of clearance.
Existing traffic volumes and the 85`h percentile speeds are shown on the map below:
,•,,�� 8000 vpd LITTLE
,p� v •TyG
4} 11000 vpd 1 14000 vpd
39 mph EB o 45 mph EB
.42 mphWB� n 39mph WB
_
—� ' MARiiH0.M
Q
a 1 S GROVE .KD
a ]4❑ -_ � i1HPfN .�
g o =
4100 vpd: P 9
a7H 1
Widths of roadway section measured at various locations are shown on the map below:
P
41 it
41 5 ft
42 ft.
MARKHAM
1
I 41.5 ft.
:Kp
Y
LINDEN � Y
2
O
Fig. 1: Utility Poles on North-
side
Fig.2: Steep Slope and Utility
poles on South -side
h
Fi
�d
- i•r: c•r.r.
t
Bike -lane Design Requirements:
AASHTO standards (attached) require a minimum width of 5 ft. for any bike lane facility. For streets with
higher traffic volumes and speeds, the minimum width requirement increases to 6 ft. Since Markham is
a Minor Arterial with a significant amount traffic (14,000 vpd) that includes buses and larger commercial
vehicles, bicycle lanes will have to beat least 6 ft. wide. In order to implement a road -diet, assuming 11
�i
a�
- i•r: c•r.r.
t
Bike -lane Design Requirements:
AASHTO standards (attached) require a minimum width of 5 ft. for any bike lane facility. For streets with
higher traffic volumes and speeds, the minimum width requirement increases to 6 ft. Since Markham is
a Minor Arterial with a significant amount traffic (14,000 vpd) that includes buses and larger commercial
vehicles, bicycle lanes will have to beat least 6 ft. wide. In order to implement a road -diet, assuming 11
ft. travel lanes and a 12 foot center -turn lane, the total required width would be 46 ft. minimum.
However, of the several locations measured on Markham, the highest measured width was only 43 ft.
with some other locations measuring as low as 41.5 ft. This makes it practically impossible to fit in bike
lanes and travel lanes of required minimum widths.
Impact on Roadway Capacity
Traffic Engineering also conducted a Level of Service analysis to determine if the road -diet option would
be able to handle existing traffic on Markham and Kavanaugh, without creating serious congestion
problems. At the intersection of Markham and Kavanaugh, the eastbound Kavanaugh approach has dual
lanes. Eastbound traffic on Kavanaugh during the AM peak hour is close to 800 vehicles. With the
elimination of one of the thru lanes on Markham and Kavanaugh, the level of service goes down to F.
Approach delays (attached) at this intersection increases to more than 4 minutes per vehicle on normal
days. In case of increased traffic due to incidents on 1-630 or Cantrell Rd., the delay may double or triple
during peak hours.
Traffic simulation model shows queuing in excess of 3100 ft. on Kavanaugh (beyond Fairfax) and in
excess of 2500 ft. on both approaches of Markham (beyond Barton and Valentine). With queues this
long, numerous side streets along Kavanaugh and Markham will be blocked on a daily basis during AM
peak hours.
North of 1-630, Markham St. and Cantrell Rd. are the only east -west arterials that serve a significant
amount of vehicular traffic. Whenever there are incidents on 1-630, drivers routinely take detours to go
on arterials such as Markham or Cantrell. On such days when there is even more traffic, the queuing
problem on Markham may get so bad that it may begin to block north -south streets and result in traffic
gridlocks.
Following are some of the negative impacts that will be faced by the motorists and residents on a daily
basis, because of reduced roadway capacity and resulting congestion:
■ Increased road user costs because of wasted fuel and time due to added delay at the
intersections.
• Significant increase in air pollution and noise pollution in residential area because of idling
vehicles.
• Significant increase in response time for emergency responders i.e. Fire trucks, ambulances,
police.
Conclusions:
1. At present, Markham St. in the Stifft Station area is not wide enough to accommodate bike lanes
and vehicle lanes that satisfy minimum AASHTO requirements.
2. Assuming roadway widening in the future to meet minimum AASHTO requirements, roadway
capacity analysis and simulation models show that converting Markham to a three -lane section
will severely impact traffic flow resulting in very long queues both on Markham and Kavanaugh.
Recommendations:
Based on Markham Street's deficient roadway geometry, bike lanes should not be installed at this time.
Traffic Engineering strongly recommends against Installation of sub -standard bike lanes as they will
create an unsafe situation for bicyclists as well as other road users.
Even if the roadway were widened in the future to accommodate standard bike lanes, the traffic volume
at the intersection of Markham and Kavanaugh cannot be handled with a three -lane section. As
mentioned above, significant queuing at this intersection will have numerous negative impacts including
increased emergency response time. Because of these negative consequences, Traffic Engineering
recommends that an alternate route be identified for bike lane installation.
Method ail is siutplc. and bike lane marking stan-
dards are outlined in Lesson 19, Method #2 involves
reconstruction (standards also outlined in Lesson
I91. In many instances, existing curb. -to -curb width
allo%vs only Method ria to be comidered.
Where existing width doesn't allow (till standards to
be used, ii may be possible to modify portions of
the roadway to accommodate bike lanes. Most
States use the following standards: 4 -:1 -meter (14-
ftbn) center tum Lutes, 3.6 -meter (12 -loco travel lanes,
1.8 -meter (ti-fbot) bike lanes, and 2.4-tnetcr (l1-
fiwo parking lanes,
These guidelines should be; used to determine how
the roadway can be modified to accommodate bike
lanes without significantly affecting the safety or
operalion of tltc roadway. Keduccd travel -lane
widths arcw•ithinAASIIJ'O minimums,
h is important to use r oot! judgment, and each
prvijcet should he reviewed by a irailic engincee
■-ea
1
t
on
�--+>—
Reduced traveflene widths-
20.3
idths
20.3 Reduce Travel -Lane
Widths
The need for full -width travel lanes decrLases with
speed:
Up to 40 kn A (25 lnph): Travel lanes may be
reduced to 3 or 3.2 tnetcr (10 or 10.5 tial).
50 to 65 knlh 130 to 40 tnph). 3.3-nt (II-fioot)
travel lanes and 3.6 -meter (12 -foot) center turn
lanes may he acceptable.
70 knt/h (45 ntph) or greater: Try to maintain u
3.6-ntctcr (12 -foo") uutsidc irnvcl lane and 4.2-
ntcler (14 -foot) center turn lane if there are
high truck volumes,
0ErOfi"
f
z
�w-3.3m-Ya-3.1m-r �.,-0.3m-,s r=•9:1 hi
AFTER:
a---. 4 2 m —1— 3.6 m 3,6 m I's rsv
Travel lanes reduced from four to three on a one-way street
20.4 Reduce Number of
Travel Lanes
iw'l'any one-way couplets were originally two-way
streets. This can result in an excessive number of
travel latter in one direction. A srttdy will dcictmine
if traffic can he handled with one less lane.
On two-way streets with four travel lanes and a
significanE nurnbcr of left -him movements, restriping
for a center turn lane, two travel lanes, and two bike
lanes can often improve traffic flow.
BEFORE:
Fin+Lit
1127 112'1 0 21
AFTER.
p.
Ir
r'(412
83.Gm-..e-3.0nT i 3.Gm-- 1.9M
(6') (12'). (127 112`) 157
Travel lanes reduced from fou to two, with center turn lane.
FFlVL'A
r=1
Lanes, Volumes, Timings
2: Markham & Kavanaugh lQW2014
_)r _. *-
L" GM
-
L"Gnw
EBL
EST
WBT
VYER
SEL
SER .
Lane Conhgurati ris
+
4
I
Volume (vph)
0
574
461
117
743
Ideal: Row (vphpl)
1200
1230
1200
1214
1203
1200
Lane Widthfff)
10
10
10
10
t0
10
Lane UN -Factor
1.00
1.30
1.00
1:00
1 00
11104
Fri
0,973
Fit Protected
0.950
Said Flaw (pfo1)
0
1098
1068
0
1043
0
Flt Permitted
0.950
Said Flow (perm)
0
1398
10668
0
1443
0
Right Turn on Red
No
NO
Satd Flow (RTOR)
Link Speed (mph)
30
30
30
Link Distance (ft)
1.017
togs
136
Travel Time (s)
23.1
25.0
3.1
Peak Hour Factor
0.92
0.92
092
0.92
0.92
0,42
Adj. Flow (vph)
0
624
$01
127
803
0
Shared Lane Traffic (%)
Lane Group Flow (vph)
0
524
628
0
80a
0
Enter Blocked Intersection
No
No
No
No
No
No
Lane Alignment
Left
Left
Letl
Right
Leh
Right
Medan Wtdth(R)
0
0
10
Link Off;et(fl)
r
0
0
Crosswalk Width(it)
16
16
16
Two way Left Tarr; Lane
Headway Factor
191
1.61
191
1.91
191
1 91
Turning Speed (mph)
15
9
1s
p
Tum Type
Protected Phases
4
s
6
Permitted Phases
Minimum Split (s)
20.0
20.0
20.0
Total Spkt (s)
0.0
4110
430
0.0
57-0
0.0
Total Split (%)
D -OSE
430%
430%
0.0%
57.0%
0.0%
Maximum Green (s)
39.0
39.0
53.0
Yellow Time (s)
3-5
3.5
3.5
All -Red Time (s)
;-5
0.5
0-6
Lost Time Adjust is)
0.0
00
0.0
0.0
0,0
0.0
Total Lostrime, (s)
4.0
4.0
4.0
4.0
4.0
4.0
LeadlLag
Lead -Lag Optimize?
Walk Time (s)
5,0
5.0
50
Flash Dont Walk (s)
110
11.0
11.0
Pedestrian Calls (#lhr)
0
0
0
Act Efict Green (s)
39.0
38-0
53.0
Actuated g1C Ratio
0.39
0.39
0,53
vk Ratio
1.46
151
1.45
Coarol Delay
258.0
266.7
241-3
Queue Delay
00
0.0
0.0
Total Defay
246.0
266.7
2413
212012014 Markham R
,�yr>£hra 7 - Report
Page 1
Lanes, Volumes, Timings
2: Markham & KavorlAu h 212.1112014
L*S'&+ 'EBL EBT WET WBR SEL SFR
LDS F F F
ApprCar.hUay 24.0 200:7 2413
ApRWO LDS F F F
droarsecCan Summary
Area Type: Olney
Cycle Length 10'�
Actvaled Cycle Lengm- 100
Or15et: 57 [571h�. Wwe€mt 10 phase 4 53T and R WBT, $13401 Green
HaUaI �Yda. 150
Control Tyfe. PfWied
MaXTnum VIC Raeo: 1.51
Interwfion Signet Ntay. 230.5 Ince€sec4on LOS: F
Inlemecom Cap" U &farm 121.5% ICU Level ofService H
Ana!ysi, Feud lminy I3
3 and Phases: 2: Marham & Kavanaugh
94
c i
212012014 Markham
Synchry 7 • Repoft
Page 2