HomeMy WebLinkAboutDiscussion and Direction To City Manager( 0
OHKOH
ON THE WATER
City of Oshkosh - Transportation Department
926 Dempsey Trail, Oshkosh, WI 54902 (920) 232 -5342 (920)232 -5343 fax
MEMORANDUM
TO: Honorable Mayor and Members of the Common Council
FROM: Christopher Strong, P.E., Director of Transportation
DATE: October 22, 2010
RE: TEMPORARY SIGNAL AT WESTHAVEN DRIVE AND 9 TH AVENUE
Over the last several months, the City Manager has presented to the Council a variety of
information about the temporary signal which was installed at the intersection of Westhaven
Drive and 9 th Avenue, and was recently deactivated. The purpose of this memo is to compile all
of this information into a single document, and to address the potential for a permanent signal at
this location.
Temporary Signal
The City has been working with the Wisconsin Department of Transportation for several years in
preparation for the US 41 reconstruction project, in part to help address the impacts of
construction activity on our local street network.
In 2009, in anticipation of the following year's reconstruction of the Witzel Avenue and 20
Avenue overpasses, the City contacted the East Central Wisconsin Regional Planning
Commission to model how the overpass closures might affect traffic on other roads in the City.
This analysis projected that the intersection of Westhaven Drive and 9 Avenue would be
significantly impacted by the construction project. The estimated traffic impacts are shown in
Table 1.
Table 1: Projected Traffic Impact of US 41 Construction at Westhaven Dr. and 9th Ave.
Approach to Intersection
2006
Daily Volume
% Change due to Construction
2010 1
2011
2012
Northbound Westhaven Drive
1,700
9%
-21%
31%
Southbound Westhaven Drive
2,000
10%
-49%
128%
Westbound 9 th Avenue
6,500
51%
-59%
94%
Eastbound 9 1h Avenue
1 4,600
1 85%
-60%
1 54%
2010 - Assumes closure of both Witzel Avenue and 20th Avenue
2011 - Assumes closure of 9th Avenue
2012 - Assumes closure of STH 21
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
With these results, the City approached WISDOT about using project funds to support the cost of
a temporary signal installation at this intersection. Under the typical municipal cost - sharing
agreement, this would allow 90 percent of the costs to be borne by the state. City staff developed
a cost estimate of $16,000 for installing a temporary intersection, based on using a combination
of in -stock materials and material to be ordered. (City electricians installed the signal; the cost of
using City equipment and staff was not included in this cost.)
The state would be willing to apply the same dollars toward a permanent signal; however, they
would have only matched 90 percent of the costs for the temporary signal. This meant that all of
the additional dollars required to make the signal conform to standards for a permanent signal
would have come from local funding. This would have involved upgrading the poles, cabinet,
controller, wiring and pedestrian signal heads, all of which would have added cost to the project.
From the City's perspective, it did not make sense to consider investing this additional money
unless the signal was warranted at this location.
Past Analyses of Signal Warrants
The intersection of Westhaven Drive and 9` Avenue has been considered as a candidate for a
traffic signal for many years, with review by the Traffic Review Advisory Board on at least four
separate occasions from 2002 through 2005. In each analysis, the signal warrants were not
satisfied for the intersection, and the Board recommended against signalizing the intersection.
Since the intersection didn't satisfy signal warrants but there were citizen concerns about safety
and delay at the intersection, City staff considered installing a roundabout at this location. To
study the effectiveness of this alternative, the City engaged with a consulting firm (Strand) to
conduct an Intersection Control Evaluation (ICE). The ICE is a standard practice in Wisconsin by
which several alternative methods of controlling an intersection are compared for their potential
effects on safety and delay, and their associated costs.
Strand completed their study in July 2009. Their study used traffic count data collected by the
City to look at current conditions, and then applied traffic growth rates estimated from previous
traffic counts to project conditions for the year 2030. To understand the findings of their report, it
is necessary to define a couple of terms. The Manual on Uniform Traffic Control Devices
(MUTCD) is adopted by the Federal and State government and provides standards and guidance
related to signage, pavement marking, signals and similar devices which are used to direct and
guide traffic. This manual includes a series of warrants for when traffic signals may be
appropriate at a given location. (Specific warrants will be discussed later in this memo.) Level of
service (LOS) is a qualitative measure that helps to assess the relative quality of traffic
operations. The level of service is assigned on an A through F scale, with A signifying free flow
conditions, and F signifying a breakdown in flow. Typically, the goal is to attain a level of
service of D or better.
To summarize, the main findings of the Strand study were as follows:
1. The existing and future traffic volumes at the intersection are not anticipated to
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
satisfy any of the MUTCD [Manual on Uniform Traffic Control Devices] warrants
for implementation of signals.
2. Traffic modeling of the existing geometry indicates that both approaches of
Westhaven Drive operate at LOS [Level of Service] F during the peak hour periods in
2009 and 2030. However, because of the minimal amount of traffic on Westhaven
Drive, signals are not warranted according to the MUTCD.
3. Modeling indicates implementation of signals provides LOS A operations with 2030
design year traffic volumes. Projected costs are as follows:
• Signals Only: $190, 000
• Signals with Geometric Enhancements: $612, 000
4. Implementation of either a single -lane or dual -lane roundabout provides LOS A
operations with 2030 design year traffic volumes. Projected costs are as follows:
• Single -Lane Roundabout: $689, 000
• Dual -Lane Roundabout: $695, 000
Strand's findings may be summarized as follows. There are difficulties in peak hour traffic for
Westhaven Drive at this intersection. A signal and roundabout would both be effective in
eliminating this peak hour delay problem. However, the short durations of peak hour congestion
are not enough to justify, based on national and state standards, the installation of a signal at this
location. The roundabout, because it would involve additional right -of -way acquisition, would
have a higher construction cost. Because of the complexity of constructing a roundabout, it
would make sense to defer construction until other construction work is going on in the vicinity.
The City presented the findings of the Strand report, along with a recommendation for a
temporary signal at this intersection, to the Traffic Review Advisory Board in October 2009. At
that time, no Board member requested that the intersection be studied further for a permanent
signal.
Current Analysis of Signal Warrants
Section 4C.01 of the MUTCD introduces the concept of signal warrants with the following
language (emphasis added):
The investigation of the need for a traffic control signal shall include an analysis of
factors related to the existing operation and safety at the study location and the potential
to improve these conditions, and the applicable factors contained in the following traffic
signal warrants:
• Warrant 1, Eight -Hour Vehicular Volume
• Warrant 2, Four -Hour Vehicular Volume
• Warrant 3, Peak Hour
• Warrant 4, Pedestrian Volume
• Warrant 5, School Crossing
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
• Warrant 6, Coordinated Signal System
• Warrant 7, Crash Experience
• Warrant 8, Roadway Network
• Warrant 9, Intersection Near a Grade Crossing
The satisfaction of a traffic signal warrant or warrants shall not in itself require the
installation of a traffic control signal.
A traffic control signal should not be installed unless one or more of the factors
described in this Chapter are met.
A traffic control signal should not be installed unless an engineering study indicates that
installing a traffic control signal will improve the overall safety andlor operation of the
intersection.
A traffic control signal should not be installed if it will seriously disrupt progressive
traffic flow.
The study should consider the effects of the right -turn vehicles from the minor - street
approaches. Engineering judgment should be used to determine what, if any, portion of
the right -turn traffic is subtracted from the minor - street traffic count when evaluating the
count against the signal warrants listed [earlier].
The City's practice has been to study an intersection to determine whether a signal is appropriate,
and to present the results of that study to the Traffic Review Advisory Board. If one or more
warrants is satisfied, then the Board typically forwards a positive recommendation to the
Council.
It was noted earlier that previous analyses from 2002 to 2009 found that the intersection of
Westhaven Drive and 9 1h Avenue has never satisfied a warrant for a traffic signal. The following
is a current assessment of how the intersection performs on each warrant.
Warrant 1: Eight -Hour Vehicular Volume. This warrant is based on having a sufficient traffic
volume on both streets at a given intersection over a minimum of eight hours of the day. Table 2
summarizes traffic volumes at this intersection as collected in the last couple of weeks.
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
Table 2: Hourly Traffic Volumes at Westhaven Drive and 9th Avenue, 2010
Satisfying this warrant would require:
a) eight hours each day of 600 vehicles per hour on 9 1h Avenue and 200 vehicles per hour on one
of the Westhaven Drive approaches;
b) eight hours each day of 900 vehicles per hour on 9 th Avenue and 100 vehicles per hour on one
of the Westhaven Drive approaches; or
c) 80 percent of the volume necessary to meet condition a) and 80 percent of the volume
necessary to meet condition b).
Neither condition a) nor b) is met for any hours. Condition c) is met for only 7 hours for part a)
and only 4 hours for part b). Therefore, this warrant is not satisfied.
Warrant 2: 4 -Hour Vehicular Traffic Volume. This warrant is also based on large volumes of
intersecting traffic, and looks at hourly traffic during any four hours of a given day. Compared to
Warrant 1, this warrant looks at both directions of traffic on the minor street. To satisfy this
warrant, there must be four points above the curve shown in Figure 1. Since only three points are
above the curve, this warrant is not satisfied.
City of Oshkosh — Department of Transportation
9th Avenue
Westhaven Drive
Time
Eastbound
Westbound
Total
Northbound
Southbound
Total
12:00 AM
17
37
53
4
9
13
1:00 AM
7
16
23
2
8
10
2:00 AM
7
23
29
2
3
5
3:00 AM
14
13
26
3
12
15
4:00 AM
34
21
55
4
18
22
5:00 AM
90
109
199
17
39
56
6:00 AM
234
170
404
58
66
123
7:00 AM
400
324
724
142
115
256
8:00 AM
246
310
556
91
114
205
9:00 AM
226
283
509
65
137
202
10:00 AM
245
311
556
78
146
224
11:00 AM
274
314
588
67
166
232
12:00 PM
254
375
629
77
158
235
1:00 PM
233
377
609
84
163
247
2:00 PM
284
425
709
79
185
264
3:00 PM
336
491
827
88
192
280
4:00 PM
350
532
882
90
187
277
5:00 PM
325
524
849
93
188
281
6:00 PM
245
399
644
93
139
232
7:00 PM
149
284
433
48
100
148
8:00 PM
98
228
326
33
85
118
9:00 PM
65
166
231
23
45
68
10:00 PM
47
112
159
18
32
51
11:00 PM
36
74
110
6
17
23
Total
4,214
5,914
1 10,128
1,263
2,322 1
3,585
Satisfying this warrant would require:
a) eight hours each day of 600 vehicles per hour on 9 1h Avenue and 200 vehicles per hour on one
of the Westhaven Drive approaches;
b) eight hours each day of 900 vehicles per hour on 9 th Avenue and 100 vehicles per hour on one
of the Westhaven Drive approaches; or
c) 80 percent of the volume necessary to meet condition a) and 80 percent of the volume
necessary to meet condition b).
Neither condition a) nor b) is met for any hours. Condition c) is met for only 7 hours for part a)
and only 4 hours for part b). Therefore, this warrant is not satisfied.
Warrant 2: 4 -Hour Vehicular Traffic Volume. This warrant is also based on large volumes of
intersecting traffic, and looks at hourly traffic during any four hours of a given day. Compared to
Warrant 1, this warrant looks at both directions of traffic on the minor street. To satisfy this
warrant, there must be four points above the curve shown in Figure 1. Since only three points are
above the curve, this warrant is not satisfied.
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
w
°
500
a
>
°
v
400
H
u)
—
w
300
W
0
■
200
H
Q
- --
- -__
- --
N
Q
a
100
-- -
-
-
O
'=
Z_
m
0
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
M 't to (0 1` M a) O r-_ N M IT
r T r V V
MAJOR STREET - Total of Both Approaches (vph)
— - 2+ Lanes & 2+ Lanes ■ Data Points
Figure 1: Evaluation of Warrant 2, Westhaven Drive and 9th Avenue, 2010
Warrant 3: Peak Hour. This signal warrant is intended for use at a location where traffic
conditions are such that for a minimum of 1 hour of an average day, the minor - street traffic
suffers undue delay when entering or crossing the major street. According to the MUTCD, "This
signal warrant shall be applied only in unusual cases, such as office complexes, manufacturing
plants, industrial complexes, or high- occupancy vehicle facilities that attract or discharge large
numbers of vehicles over a short time." As such, this warrant is not applicable in this case.
Warrant 4: Pedestrian Volumes. This warrant requires minimum pedestrian volumes during a
peak hour or over a four -hour period, as well as a lack of gaps in traffic in which pedestrians may
safely cross. The requirement is for there to be 190 pedestrians crossing in a single hour or 100
pedestrians in each of four hours during a day. This is a threshold that is difficult to meet in a
lower land use density setting as it is near this intersection. Observations at the intersection of
Westhaven Drive and 9 1h Avenue indicate that pedestrian volumes come nowhere close to
meeting this requirement.
Warrant 5: School Crossing. This warrant is a variant of the previous warrant and focuses on
pedestrian crossings toward a school. As this intersection is not near a school, this warrant is not
applicable.
Warrant 6: Coordinated Signal System. This warrant can be used to help traffic progression
through signals by preserving platooning of vehicles. Given that the closest signal is 1 /2 mile
away, this warrant is not applicable.
Warrant 7: Crash Experience. Traffic signals can be used to improve intersection safety. The
following must be satisfied:
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
Five or more reported accidents of types susceptible to correction by a traffic signal within a
twelve month period;
the volume of traffic is at least 80 percent of the required level for the minimum vehicular
volumes from Warrant 1; and
adequate trial of alternatives with satisfactory observance and enforcement has failed to
reduce the crash frequency.
Table 3 summarizes the crash history at this intersection from 2002 to date.
Table 3: Number of Crashes at Westhaven Drive and 9th Avenue, 2002 to present
Year
# of Crashes
2002
7
2003
3
2004
7
2005
3
2006
4
2007
10
2008
6
2009
3
2010 to date
3
Crash records were reviewed from 2007 to the present to see whether there were patterns of
crashes which could be alleviated through installation of a signal. The data are summarized in
Table 4.
Table 4: Crash Frequency and Type, Westhaven Drive and 9th Avenue, 2007 -2010 (to date)
Crash Description
2007
2008
2009
2010
Total
Westhaven Traffic Violates Right -of -Way
3
4
1
2
10
SB Westhaven
1
2
0
2
5
NB Westhaven
2
2
1
0
5
9th Avenue Turned Left in Front of Opposing Traffic
4
1
2
1
8
EB Left
1
0
2
1
4
WB Left
3
1
0
0
4
NB Westhaven Vehicles Sideswipe
1
1
0
0
2
Rear -end Crashes
2
0
0
0
2
Total
10
6
3
3
22
The most frequent type of crash, where a vehicle leaving Westhaven Drive violated right -of -way
and either struck or was hit by another vehicle, has occurred ten times between 2007 and the
present, with a maximum annual occurrence of four crashes. In a well- designed signal, this type
of crash should occur less frequently, but will not necessarily be eliminated.
The second most frequent type of crash involves when a left - turning vehicle on 9 th Avenue
turned in front of, and was struck by, oncoming traffic. This type of crash would still be prone to
occur at this intersection even with a signal; in fact, one of these crashes occurred this year while
the signal was in operation. Reducing this type of crash would require adding a left -turn phase
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
signal, which would increase further delay for some 9 th Avenue traffic, and/or adding left -turn
lanes, which would significantly increase the cost of the signal.
The third most frequent type of crash involved northbound vehicles which decided to make a
lane change at the last minute, before entering the intersection. This occurs at both signalized and
unsignalized intersections. The final crash type at this intersection, rear -end crashes, may occur
more frequently at signalized intersections.
Since the crash experience does not satisfy the first part of this warrant, the other parts of this
warrant were not examined.
It should be noted that traffic signals are not a panacea for accidents. In Oshkosh in 2009, of the
20 intersections with the highest number of crashes, 18 were controlled by traffic signals.
Warrant 8: Roadway Network. A traffic signal may be installed to encourage concentration and
organization of traffic flow on a roadway network. This warrant is not applicable for an isolated
signal like this.
Warrant 9: Intersection Near a Grade Crossing. There is no railroad crossing near this
intersection, so this warrant would not be applicable.
In summary, a current analysis for this intersection shows that none of the signal warrants are
satisfied.
Unwarranted Signals
A signal may be installed and operated even if doesn't satisfy the warrants, and it can offer
benefits at certain times to certain road users. However, any such decision needs to be made in
full consideration of the related issues that would result. With this location, here are some
adverse consequences to keep in mind.
• The signal will not help traffic flow for the roughly 75 percent of traffic which goes through
this intersection on 9 th Avenue. It will not reduce delay and will, for many motorists, increase
delay.
• The signal will increase delay for Westhaven Drive traffic when there is no cross - traffic on
9 th Avenue.
• The signal will make little difference for the 60 to 75 percent of northbound traffic on
Westhaven Drive which turns right.
• The signal will increase delay for pedestrians who cross Westhaven Drive, unless they choose
to disobey the law and cross against a signal.
• The signal may increase the number of certain types of crashes, including lower severity year-
end crashes as well as higher- severity crashes such as red -light running.
City of Oshkosh — Department of Transportation
Temporary Signal at Westhaven Drive and 9th Avenue
• To make the signal permanent would cost tens of thousands of additional dollars at a
minimum. If geometric improvements are made in order to address crashes involving
eastbound or westbound left- turning vehicles, this would increase the cost by hundreds of
thousands of dollars.
• In addition to the installation and purchase cost, the signal would require ongoing operation
and maintenance cost. This would include factors such as signal pole knockdowns, mandated
testing of signal monitors and equipment, cabinet cleaning, periodic re- timing, responding to
power outages, replacement and cleaning of signal lenses, and electricity costs. This would
also include the unexpected issues, such as lightning strikes this summer which apparently
damaged the temporary intersection's detection equipment.
Recommendation
The department recommends that a temporary signal be maintained at this intersection through
the duration of the US 41 construction project, as was outlined in a newsletter article from the
City Manager to the Common Council last November. This would mean that the signal remains
inactive now until 2012 when construction activity related to Highway 21 starts. At the
conclusion of the 2012 work, the City will able to retain the equipment used in the temporary
signal for uses at other signalized intersections.
The department recommends against signalizing this intersection on a permanent basis until at
least one warrant is satisfied. As it is within the Traffic Review Advisory Board's responsibility
to review intersections for signalization, this information should be presented to the board for
their consideration. If the Board recommends against signalization, staff will continue to collect
traffic and crash data and monitor the intersection to determine whether it is close to meeting
warrants.
City of Oshkosh — Department of Transportation