Zone 8 First Post Study - NEW
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Purpose
The purpose of the first post-study is to evaluate how the neighborhood streets
are operating since making both intersection traffic control and speed limit
modifications. This is done by collecting vehicular volume and speed data
through the use of mechanical traffic counters and receiving accident reports
from the Police Department. The data is then analyzed to verify traffic is
flowing efficiently and safely in the neighborhood. It is also analyzed to
determine any locations that have experienced a noticeable increase in daily
volume and/or average speed. These locations will then be further examined as
part of a second post-study.
The first post-study will be performed approximately 6 months after making the
sign changes. Unless a significant issue is evident after reviewing the data, no
further sign changes will be made during this initial review. During this time
period, many motorists are still becoming accustomed to the changes and the
results may not be indicative of future traffic conditions. For this reason, a
second post-study will be performed approximately 12 months after making the
sign changes. Once a second post-study is completed, a Neighborhood Meeting will
be held to provide an opportunity for residents in the neighborhood to share
their thoughts with the Village. The Village Board of Trustees will then decide
whether any further sign changes should be made in the neighborhood. |
Summary
Based on the collected data from the first post-study, no sign changes are
recommended at this time in the neighborhood. The first post-study involved
gathering vehicular volume and speed data at 46 locations, monitoring pedestrian
activity at 4 intersections, and reviewing accident records at all 61
intersections in the neighborhood. Below is a summary of the results:Daily
Volume -
Stayed consistent or decreased at 38
locations (83%)
Increased by 10% or more at 8 locations
(17%)
Average Speed -
Stayed consistent or decreased at 45 locations
(98%)
Increased by 5mph or more at 1 location (2%)
Accident Rate (# accidents per month in the neighborhood) -
Before the sign changes: 1.42
Since the sign changes: 0.67
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Traffic
Volume Data
Traffic volumes fluctuate on a daily basis and, as such, any increase or
decrease in traffic is not necessarily attributed to the intersection traffic
control and speed limit modifications. Traffic volumes typically vary by month
of the year, day of the week and time of the day. And a ten to fifteen percent
variation in traffic volumes is typical in suburban areas.
Any location that experiences an increase in traffic volume of ten percent or
more will be reexamined as part of the second post-study. The ten percent
increase was selected as it represents the lower threshold of the ten to fifteen
percent variation in traffic volumes that is typical in suburban areas. It
should not be interpreted as the threshold that signifies a concern. Many
factors affect traffic volumes including those discussed above as well as
roadway classification (collector vs. local) and nearby land use (residential,
commercial, schools, etc.).
Of the 46 locations where traffic volume data was collected, daily volumes
decreased at 29 locations and increased at 17 locations. A comparison of the
daily volumes before and after the sign changes indicates that as a whole
traffic volume has remained relatively stable. Of the 17 locations that
experienced an increase in traffic volume, only 8 locations saw a ten percent or
more increase. The table below highlights those streets that have experienced an
increase in traffic volume of ten percent or more and will be reexamined as part
of a second post-study.
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Daily Traffic Volume |
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Street |
Between |
And |
Before |
After |
Percent
Increase |
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Eastwood Avenue |
Kensington Road |
Highland Street |
360 |
420 |
16.7 |
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Elmhurst Avenue |
Gregory Street |
Isabella Avenue |
1280 |
1485 |
16.0 |
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Elmhurst Avenue |
Kensington Road |
Highland Street |
945 |
1140 |
20.6 |
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Fairview Avenue |
Kensington Road |
Highland Street |
910 |
1060 |
16.5 |
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Fairview Avenue |
Memory Lane |
Gregory Street |
1115 |
1285 |
15.2 |
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Forest Avenue |
Highland Street |
Memory Lane |
630 |
685 |
10.4 |
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Gregory Street |
Fairview Avenue |
Prospect Manor Ave |
1655 |
1910 |
15.4 |
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Gregory Street |
MacArthur Blvd |
Oak
Street |
1160 |
1345 |
15.9 |
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To view the daily traffic volumes on all streets included
in the first post-study, click on the link below.
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Traffic Speed
Data
Similar to traffic volumes, traffic speeds also will vary by season or month of
the year, day of the week and time of the day. As such, any increase or decrease
in traffic speeds is not necessarily attributed to the speed limit and
intersection traffic control modifications.
Any location that experiences an average speed of 30 mph or greater and/or an
increase in average speed of 5 mph or more will be reexamined as part of the
second post-study. The 30 mph average speed was selected as it represents a 5
mph increase over the 25 mph posted speed limit in the neighborhood and is
higher than the average speed seen on most neighborhood streets. Furthermore,
the increase in average speed up to 5 mph was selected as an acceptable range
because of the expected variability in speeds. Average speeds exceeding the
criteria should not be interpreted as the threshold that signifies a concern.
Many factors affect traffic speeds including those discussed above as well as
weather and the roadway’s physical characteristics such as width, number of
travel lanes, hills, curves and condition.
Of the 46 locations where traffic speed data was collected, average speeds were
below the limits described above at 42 locations. A comparison of the average
speeds before and after the sign changes indicate that as a whole traffic speed
has remained stable. Of the 4 locations that exceeded the criteria, 3 locations
experienced an average speed of 30 mph or greater and 1 location experienced an
increase in average speed of 5 mph or more. All 3 locations that experienced an
average speed of 30 mph or greater were on the long blocks between Kensington
Road and Highland Street. And it should be noted that intersection traffic
control and speed limits were not altered along these blocks. The 1 location
that experienced an increase in average speed of 5 mph or more is still at a
level that is typical for neighborhood streets. The tables below highlight those
streets that have exceeded the traffic speed criteria and will be reexamined as
part of a second post-study.
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Average
Speed 30 mph or Greater |
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Average Speed (mph) |
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Street |
Between |
And |
Direction |
Before |
After |
Increase (mph) |
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Elmhurst
Avenue |
Kensington Road |
Highland
Street |
Southbound |
28 |
30 |
2 |
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Pine
Street |
Kensington Road |
Highland
Street |
Southbound |
27 |
30 |
3 |
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Prospect
Manor Ave |
Kensington Road |
Highland
Street |
Southbound |
29 |
30 |
1 |
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Increase in Average
Speed 5 mph or More |
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Average Speed (mph) |
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Street |
Between |
And |
Direction |
Before |
After |
Increase (mph) |
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Henry
Street |
Elmhurst Avenue |
Ridge
Avenue |
Westbound |
15 |
20 |
5 |
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To view the average traffic speeds on all streets included in the first
post-study, click on the link below.
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Accident Data
At the time of the first post-study, 9-months had passed since implementation of
the intersection traffic control and speed limit modifications. A total of 6
accidents had occurred at the 61 intersections in the neighborhood during this
time period. As a whole, the neighborhood has experienced a low incident of
accidents since the sign changes. The accident data indicates that the
consistent set of traffic regulations have created a more orderly flow of
traffic and enhanced safety. Nevertheless, accident records for the entire
neighborhood will be reexamined as part of a second post-study. The table below
summarizes the accident data.
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Total Number of
Accidents |
Number of
Accidents Per Month in the Neighborhood |
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3 Years Prior to
Sign Changes |
51 |
1.42 |
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9 Months Since
Sign Changes |
6 |
0.67 |
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53% reduction in accident rate |
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Conclusion
The results of the first post-study indicate that the operating characteristics
within the neighborhood have generally improved since implementation of the
intersection traffic control and speed limit modifications. Thus far, it appears
the sign changes have improved the flow of traffic within the neighborhood and
enhanced safety. Overall, traffic volumes and speeds are within acceptable
ranges and the accident rate has decreased. While some streets have experienced
an increase in traffic volume and/or speed, the number of such locations has
been very limited. These locations will be given further attention as part of a
second post-study that will take place approximately 12 months after the sign
changes. The second post-study will again evaluate traffic volume, traffic speed
and accident records.
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Resident Letter |
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Key People
Below is contact information for key people involved in this study:
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KLOA, Inc.
Traffic engineering consultant
Michael Werthmann
9575 W. Higgins Road
Suite 400
Rosemont, IL 60018
847-518-9990
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Village of Mount Prospect
Matt Lawrie
Traffic Engineer
1700 W. Central Road
Mount Prospect, IL 60056
847-870-5640
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Contact Us
Contact us by e-mail or phone for more details on this study.
E-mail:
Phone: 847-870-5640
Fax: 847-253-9377
Website: www.mountprospect.org
After Hours Phone (Police Desk): 847-870-5656 |
