Title
Resolution Directing the City Administrator to Review Traffic Calming, Speed Limits, and Design Speed for Road Reconstructions
Memorandum
When the City Council received the recommendations of the Pedestrian Safety and Access Task Force, it also adopted a Vision Zero goal of “zero traffic fatalities by 2025.
One important tool to prevent pedestrian fatalities is to lower traffic speeds. For example, World Health Organization data show that the chance of death for a pedestrian hit by an automobile increases as vehicle speed increases, from 5% at 20 miles per hour to 85% at 40 miles per hour. Traffic calming, speed limits, and street design are three tools to lower traffic speeds. This resolution explores ways to improve those systems.
Modifying the qualification criteria
There are a variety of traffic dynamics that can lead residents to seek traffic calming
● Consistent speeding: There is a steady stream of vehicles traveling above posted speeds.
● Jackrabbits: While most traffic may travel within 5 mph of posted speeds, the street regularly experiences vehicles travelling significantly in excess of posted speeds, such as 40mph in a 25mph neighborhood
● Rush Hour Rushing: While a street may experience appropriate speeds 22 hours per day, it experiences a significant amount of speeding during rush hours.
One of the current qualifications for neighborhood traffic calming is “15 percent of the traffic must be traveling at least 5 mph over the legal speed limit.” This criteria functions well for the problem described as consistent speeding, but is not well suited to the problems of “rush hour rushing” or “jackrabbits.” For these problems it may be useful to expand the criteria in the following ways:
● Experiences 15 percent of the traffic travelling at least 5 mph over the legal speed limit for any one hour period (to address rush hour rushing)
● Experiences 5 percent of the traffic travelling at least 10 mph over the legal speed limit (to address jackrabbits).
Furthermore, the presence of vulnerable users such as individuals with mobility impairments may also affect whether or not traffic calming is merited on a given street.
Expanding the eligible streets
Currently, traffic calming in the City of Ann Arbor is limited to streets “classified as a local street, as indicated on the State of Michigan ACT 51 maps.” Streets classified as arterials or collectors are excluded from this process. However, NACTO and the Institute of Traffic Engineers (ITE) have guidance for use or application of some traffic speed management or calming devices to be deployed on these higher-volume streets. For example, the ITE lists speed tables as appropriate for collectors (<http://www.ite.org/traffic/table.asp>).
Should Safety Require a Super Quorum and Supermajority?
The current traffic calming methodology requires a super quorum of 60% of resident homeowners responding to the second survey and a supermajority of 60% of those responding to support all or part of the project. It may be time to review if these are still the appropriate thresholds for action.
Lowering Speeds through Limits and Engineering
In 2015 Council Members Eaton and Anglin proposed a City Council resolution to reduce posted speeds in near-downtown neighborhoods to 25 mph. While this resolution was ultimately withdrawn, it did reflect both a community concern about speed limits in residential areas as well as national trends to set lower speed limits.
While some automobile advocates suggest that speeds should be set at the 85th percentile speeds, other standards exists. For example, the Federal Highway Administration’s USLIMITS2 framework calls for speed limits closer to the 50th percentile speed in areas with high pedestrian and bicycle activity.
Given this, there is merit in evaluating whether or not to allow for citizen-initiated review and lowering of traffic speeds through a process similar to the traffic calming method.
Furthermore, actual traffic speeds are significantly determined by engineering elements such as lane and pavement width and can only be affected in limited ways through modification of posted speed limits and traffic enforcement. Given the trend nationally to seek to reduce speeds to promote bicycle and pedestrian safety, it is time to evaluate if we should change what speed we engineer roads for when we reconstruct them.
Staff
Reviewed by: Nick Hutchinson, City Engineer
Craig Hupy, Public Services Area Administrator
Body
Whereas, In March 2011 the City of Ann Arbor approved a resolution proclaiming a commitment to complete streets;
Whereas, The City of Ann Arbor Sustainability Framework establishes the transportation goal to “Establish a physical and cultural environment that supports and encourages safe, comfortable and efficient ways for pedestrians, bicyclists, and transit users to travel throughout the city and region.”
Whereas, On October 5, 2015, City Council accepted the recommendations of the Pedestrian Safety and Access Task Force and affirmed the “vision zero” goal of zero traffic fatalities by 2025;
Whereas, World Health Organization data show that the chance of death for a pedestrian hit by an automobile increases as vehicle speed increases, from 5% at 20 miles per hour to 85% at 40 miles per hour;
Whereas, Residential traffic calming has shown to be a popular and effective means to address concerns over neighborhood speeds;
Whereas, The USLIMITS2 model for setting speed limits calls for setting speed limits close to the 50th percentile speeds in areas of high pedestrian and bicycle activity;
Whereas, According to the USLIMITS2 Users Guide, “Examples of areas with ‘High’ pedestrian and bicycle activity include: (1) Residential developments with four or more housing units per acre interspersed with multifamily dwellings, (2) Hotels located with 1/2 mile of other attractions such as retail stores, recreation areas, or senior centers, (3) Downtown or CBD areas, and (4) the presence of paved sidewalks, marked crosswalks, and pedestrian signals;
RESOLVED, That Ann Arbor City Council directs the Administrator to review the traffic calming process to see if the technical criteria for speeds should be expanded, the streets on which traffic calming is allowed should be expanded or allowed under a separate program, and if the second survey super quorum and supermajority requirements should be modified;
RESOLVED, That Ann Arbor City Council directs the administrator to evaluate whether or not to allow for citizen-initiated review aimed at lowering of design and posted speeds on streets with high pedestrian and bicycle activity through a process similar to the traffic calming method;
RESOLVED, That Ann Arbor City Council directs the administrator to explore the reduction of design speeds on streets with high pedestrian and bicycle activity during the engineering design of roads when they are reconstructed.
RESOLVED, That the City Administrator shall report back to City Council on these matters by November 10, 2016
Sponsored by: Councilmembers Warpehoski, Eaton, Briere, Smith, Grand, Westphal, Ackerman, Krapohl, and Mayor Taylor