CITY COUNCIL AGENDA ITEM
ACTION REQUESTED:
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Waive the first reading and pass the ordinance to establish a 25 mph speed limit for the Atwater Subdivision (requires six positive votes)
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DEPARTMENT: Transportation, Engineering and Development
SUBMITTED BY: Michael Prousa, TED Project Manager
BOARD/COMMISSION REVIEW:
On October 1, 2020 the Transportation Advisory Board (TAB) recommended approval to establish a 25 mph speed limit for the Atwater Subdivision. Approved (9-0)
BACKGROUND:
Atwater is a newer subdivision bounded by Diehl Road (north), Fairway Drive (east), North Aurora Road (south), and Shore Road (west). The streets in Atwater have been operating under the default 30 mph limit established by the Illinois Vehicle Code.
Staff from the Transportation, Engineering and Development Business Group (TED) has received several recent requests for speed limit signage in the Atwater subdivision and conducted a study to investigate the need for speed limits.
DISCUSSION:
The Study
The warrants used to establish speed limits are located in Section B of the Illinois Department of Transportation (IDOT) "Policy on Establishing and Posting Speed Limits" and the Illinois Vehicle Code. This IDOT policy uses the 85th percentile speed (the speed at which 85 percent of the vehicles are driving at or below) and other adjustment factors for potential conflicts such as the number of driveways, pedestrians, crashes, and on-street parking, to determine the recommended posted speed limit.
Traffic data was collected at three different representative locations across the Atwater subdivision: Alderleaf Lane, Balsam Cove Road, and Country Club Boulevard from July 8 - July 15, 2020. Maps are attached and findings for each street are listed below:
Alderleaf Lane
The 85th percentile speed, and the upper 10 mph pace, was 33.5 mph and 30 mph. The prevailing speed is the average of the 85th percentile and the upper 10 mph pace, which equates to 31.75 mph.
Balsam Cove Road...
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