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| Final Traffic Study |
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Summary
Per
the direction of the Village Board of Trustees, seven speed humps were installed
in May 2006 on See-Gwun Avenue between Golf Road and Lincoln Street. The
Engineering Division performed an interim traffic study in September 2006 and a
final traffic study in April 2007. Similar to the results from the interim
traffic study, the final traffic study found both vehicular speed and volume to
be lower on See-Gwun Avenue since installation of the speed humps one year ago.
Average daily traffic continues to be higher on We-Go Trail and Na-Wa-Ta Avenue,
parallel streets on either side of See-Gwun Avenue, but not equal to the
difference in volume on See-Gwun Avenue. It is believed that other north-south
streets in the neighborhood such as Lancaster Avenue and Can-Dota Avenue have
also experienced an increase in traffic since installation of the speed humps.
With respect to overall vehicular speed on adjacent streets, We-Go Trail and Na-Wa-Ta
Avenue continue to see no noticeable change.
Based on the response received from the most recent surveys, See-Gwun Avenue
residents overall continue to perceive lower vehicular volume and speed. They
also believe the street to be safer for pedestrians and bicyclists. 56% of the
returned surveys indicated a preference to have the speed humps remain.
A majority of the completed surveys from residents on We-Go Trail and Na-Wa-Ta
Avenue continue to believe there to be an increase in vehicular speed and volume
on their street since installation of the speed humps. Also, residents on these
adjacent streets are evenly split when it comes to supporting the speed humps on
See-Gwun Avenue but a majority still does not favor speed humps for their street
or throughout the neighborhood.
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Traffic
Data Collection Soon before the speed humps were installed in
May 2006, the Engineering Division gathered speed and volume data on See-Gwun
Avenue as well as two adjacent streets, We-Go Trail and Na-Wa-Ta Avenue. During
this five-day test period, school was in session and the golf course experienced
activity. In September 2006 and April 2007 after the speed humps were installed,
speed and volume data were again gathered at the same locations. Similar to the
initial study, school was in session and the golf course was busy. Click on the
map below to see the locations of the traffic counters during all three studies.
Traffic Counter Location Map
The final traffic study performed in April 2007 continues to show that since
the speed humps have been installed both vehicular speed and volume are lower on
See-Gwun Avenue. At the two locations where speed data was gathered between
speed humps (south of Go-Wando Trail and south of Sunset Road), the average
speed was down 3 and 8 mph, respectively, when comparing the April 2007 study to
the April 2006 study. Between Lincoln Street and Go-Wando Trail, the traffic
counter on See-Gwun Avenue was placed 50 from the speed hump for the purpose of
gauging speeds just before vehicles traverse the speed hump. The average
recorded speed was 18 mph. And the fourth traffic counter was placed between the
Stop sign at Council Trail and the speed hump at the top of the hill near
Lonnquist Boulevard. While the spacing between the speed humps is typically 350
to 450, the distance between the Stop sign and speed hump on this block is
575. The average recorded speed was down 1 mph. At three of the four traffic
counter locations on See-Gwun Avenue, volume was down approximately 50% when
comparing the April 2007 study to the April 2006 study. The fourth location was
near the bridge where there are no other north-south alternatives to get across
Weller Creek in the neighborhood. Still, volume was down nearly 20%. Overall,
traffic volume on See-Gwun Avenue has further decreased when comparing the
results from the final traffic study in April 2007 to the interim traffic study
in September 2006.
On We-Go Trail and Na-Wa-Ta Avenue, the average recorded speeds at all four
traffic counter locations continue to see no noticeable change. Daily traffic
volume increased on We-Go Trail and Na-Wa-Ta Avenue but not equal to the
difference in volume on See-Gwun Avenue. Volume was up anywhere between 10% and
52% when comparing the April 2007 study to the April 2006 study. It is believed
that other north-south streets in the neighborhood such as Lancaster Avenue and
Can-Dota Avenue have also experienced an increase in traffic since installation
of the speed humps. Overall, traffic volume on We-Go Trail and Na-Wa-Ta Avenue
has further increased when comparing the results from the final traffic study in
April 2007 to the interim traffic study in September 2006.
Below is a table summarizing the data of the three traffic studies. |
Summary Table |
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Traffic Volume & Speed Graphs Below are links to graphs
highlighting the traffic volume and speed data.
See-Gwun Avenue Before & After Volume Data
We-Go Trail Before & After Volume Data
Na-Wa-Ta Avenue Before & After Volume Data
See-Gwun Avenue Before & After Speed Data
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Resident Survey
In April 2007, a third survey was sent to the 98 properties along See-Gwun
Avenue to gauge the impact of the speed humps. 64% responded to the latest
survey. Overall, residents continue to perceive lower vehicular volume and speed
(Questions 1 & 2). They also believe the street to be safer for pedestrians and
bicyclists (Questions 3 & 4). With respect to fulfilling expectations, it
appears residents perceive the speed humps to have had less effect in reducing
vehicular speeds yet have had more effect in reducing vehicular volume when
comparing the April 2006 survey to the September 2006 and April 2007 surveys
(Questions 5 & 6). With respect to other issues that can be associated with
speed humps, residents continue to be somewhat concerned about emergency
response time, noise pollution, aesthetics and loss of on-street parking
(Questions 7 10).
A majority of residents on See-Gwun Avenue appear to still be satisfied with
the speed humps but support has declined over time (Question 12). 56% of the
returned surveys prefer that the speed humps remain. The table below shows the
results of the surveys.
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Resident Survey - See Gwun |
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In April 2007, a second survey
was sent to the 157 properties along We-Go Trail and Na-Wa-Ta Avenue in the
project area. 46% responded to the latest survey. Overall, residents on these
streets continue to believe there to be an increase in vehicular volume and
speed since installation of the speed humps (Questions 5 & 6). Residents were
evenly split on their support (or lack of) for the speed humps on See-Gwun
Avenue but a majority still did not believe speed humps on their street or
throughout the neighborhood would have a positive impact (Questions 7 9). The
table below shows the results of the surveys.
Resident Survey - We-Go, Na-Wa-Ta
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Analysis
Positive Impact
The two issues raised by residents of See-Gwun Avenue have been excessive
vehicular speed and volume along their street. While the primary purpose of
speed humps is to slow down traffic, they also can lower vehicular volume as
some motorists will choose alternative routes. And based on the results of the
traffic data, the vehicular speed and volume are lower on See-Gwun Avenue.
The 500 and 900 blocks of See-Gwun Avenue had traffic counters placed midway
between two speed humps. On the 500 block, the average speed decreased from 25
mph to 22 mph. And on the 900 block, the average speed decreased from 31 mph to
23 mph. In addition, excessive speeding decreased significantly along the 900
block. Before the speed humps, 43.9% of motorists were traveling 32 mph or
greater. From the April 2007 study, only 3.7% of motorists were traveling 32 mph
or greater. From the residents perspective, on a scale of 1 to 10 (1-very slow,
5-at speed limit, 10-extremely fast), when asked about the perceived vehicular
speed the average score decreased by 1.7 when comparing the survey before the
speed humps to the latest survey in April 2007.
At the four traffic counter locations along See-Gwun Avenue, volume decreased
between 16% (700 block) and 49% (400 block). This equates to a decrease in
approximately 350 550 vehicles per day depending on the section of See-Gwun
Avenue. From the residents perspective, on a scale of 1 to 10 (1-very little,
5-reasonable amount, 10-way too much), when asked about the perceived vehicular
volume the average score decreased by 1.2 when comparing the survey before the
speed humps to the latest survey in April 2007.
Not only have the speed humps impacted the vehicular speed and volume along
See-Gwun Avenue, residents have also perceived an increase in pedestrian and
bicycle safety. On a scale of 1 to 10 (1-very unsafe, 5-somewhat safe, 10-very
safe), when asked about the perceived pedestrian safety the average score
increased by 0.7 when comparing the survey before the speed humps to the latest
survey in April 2007. And on a scale of 1 to 10 (1-very unsafe, 5-somewhat safe,
10-very safe), when asked about the perceived bicycle safety the average score
increased by 1.0 when comparing the survey before the speed humps to the latest
survey in April 2007.
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Negative Impact
According to the Village Code, See-Gwun Avenue is a collector street. It
provides the only north-south connection between Lincoln Street and Golf Road
within the neighborhood. It also provides direct access to the Mount Prospect
Golf Course. And as a collector street, mobility should be encouraged to promote
the hierarchy of street classifications within the neighborhood. In other words,
collector streets are expected to experience a greater volume of traffic than
other neighborhood streets because they are designed to serve as a main link for
neighborhood traffic to get to the main roads and vice versa. While vehicular
volume has decreased on See-Gwun Avenue to the support of residents along the
street, this redistribution of traffic is not necessarily beneficial to the
neighborhood. Comparing the traffic study before speed humps to the latest study
in April 2007, vehicular volume on the two adjacent parallel streets have
increased between 10% and 52%. This equates to an increase in approximately 30
200 vehicles per day depending on the street. The 400 block of We-Go Trail which
is a narrower street than See-Gwun Avenue now experiences more daily traffic
than all studied blocks on See-Gwun Avenue except at the bridge (700 block).
Speed humps are known as a volume reducer because some motorists will choose
alternate routes. When placed on a collector street, a larger number of vehicles
will shift to other streets compared to when they are placed on a smaller local
street simply because a collector street experiences more traffic to begin with.
Even residents on We-Go Trail and Na-Wa-Ta Avenue commented in the surveys a
perceived increase in vehicular volume on their streets.
Another issue with speed humps is their affect on all motorists not just
those speeding excessively. Often times, a small percentage of careless
motorists will give the impression there is an overall speeding problem on a
street. Case in point, the traffic counter on the 500 block of See-Gwun Avenue
recorded only 6% of vehicles traveling 32 mph or greater before installation of
the speed humps. While the solution should be to correct the behavior in this
small percentage of motorists, speed humps cause all motorists, including those
normally driving at a safe speed, to drive differently. They force the driver to
traverse them at 15 mph, well below the posted speed limit of 25 mph. This rise
and fall in speed every 350 to 450 can frustrate motorists and also increases
noise pollution in the neighborhood caused by constant braking and accelerating
of vehicles.
Delaying emergency vehicle response also continues to be a concern for the
both the Fire Department and Police Department, especially with speed humps on a
collector street. Use of collector streets to get to an emergency in a
neighborhood is essential and speed humps increase their response time. Through
tests performed by the Fire Department, they have determined that the speed
humps have added over one minute for an emergency vehicle to travel from Golf
Road to Lincoln Street along See-Gwun Avenue. While one minute may not seem like
a long time, this delay could be an important factor in the outcome of an
emergency. Also, the jarring going over the speed humps can affect the
passengers and wears the emergency vehicles causing an increase in maintenance
costs. For all of these reasons, the Fire and Police Departments are not
advocates of speed humps. Even residents expressed in the surveys some concern
with potential delays with emergency vehicles caused by the speed humps.
The Public Works Department did not express significant concern with the
speed humps from an operational standpoint. Street sweepers and snow plow trucks
travel at a reduced speed and their drivers did not share any difficult
experiences over the past year. However, larger snow falls and speed humps
throughout the Village could pose concerns for their services. From a
maintenance standpoint, annual repair to the asphalt and pavement markings would
be necessary. This would be an added cost to the Village Budget.
A final issue that is worth mentioning is aesthetics. Some other traffic
calming projects completed in the Village including curb extensions and median
islands have had an element of landscaping incorporated into them. By adding
features such as trees, bushes and grass, a project can enhance the
attractiveness of a neighborhood. Speed humps, however, do not have an
ornamental feature. They are comprised of asphalt, pavement marking and signs.
This hard look can detract from the look of a neighborhood. On a scale of 1 to
10 (1-not, 5-somewhat, 10-extremely), when asked how displeased residents are
with the aesthetics of the speed humps the average score increased from 4.5 from
the September 2006 survey to 5.0 from the latest survey in April 2007.
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Conclusion
As directed by the Village Board of Trustees, the Engineering Division has
studied the impact of speed humps along See-Gwun Avenue over a one-year period.
Vehicular speed and volume data was gathered on See-Gwun Avenue as well as two
adjacent streets, We-Go Trail and Na-Wa-Ta Avenue. Also, multiple surveys were
mailed in order to get resident feedback and various Village departments
including the Fire Department, Police Department and Public Works Department
provided input on this important project. As evident from the traffic studies,
vehicular speed and volume have decreased on See-Gwun Avenue since installation
of the speed humps while vehicular volume has increased on adjacent streets. The
data and feedback from various interest groups have shown both positive and
negative results along See-Gwun Avenue and in the neighborhood.
The next step in the process will be for the Village to host a Neighborhood
Meeting. At this meeting, residents will have the opportunity to provide their
thoughts directly to the Village Board of Trustees. Your input will assist the
Village Board of Trustees in making a decision regarding the status of the speed
humps on See-Gwun Avenue as well as future consideration on other streets in the
Village. Such a meeting has been scheduled for
Tuesday, October 30th. The Neighborhood Meeting will be held in the Learning
Resource Center at Lincoln Junior High School, 700 W. Lincoln Street, and begin
at 7:00 p.m. The public is invited to attend and participate in the meeting.
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