WBWC recommends against using the 85th percentile method when determining posted speed limits on transportation corridors currently used by bicyclists, walkers, or wheelchair users, and/or where an increased pedestrian presence is desired.
WBWC, with its coalition partners, represents the interests of thousands of bicyclists and walkers throughout Washtenaw County.
One example that exemplifies the adverse impacts of the 85th percentile method for motorists can be found in Washtenaw County on M-14 near the Barton Drive entrance/exit in Ann Arbor. The speed limit was set at 55 mph to enable motorists to exit and enter the highway more safely. This location is extremely dangerous because of the design of the entrance/exit ramps, however the speed limit was raised to 65 mph due to an 85th percentile speed study in 2010. (http://www.annarbor.com/news/speed-limit-raised-to-65-miles-per-hour-on-m-14-near-barton-drive/) As you heard from the testimony of Dr. Gates to your committee on September 8th, the speed limit increase led to a significant increase in accidents along that stretch of roadway. The 85th percentile method fails to factor in numerous critical variables that are important factors in safety and we must begin to rethink the value of a method that is proving to be unsafe, not just for cyclists and pedestrians, but for motorists as well.
However, WBWC focuses on the needs of bikers and walkers, and as such, the remainder of our statement will emphasize the specific challenges the 85th percentile method poses for these user groups. Ann Arbor boasts a 4% bicycling and 16% walking commuter mode share, high above the national average. In 2008, in response to an 85th percentile study, the speed limit on North Main Street heading into downtown Ann Arbor off of M-14, was raised from 40 to 45mph. This stretch of North Main Street travels parallel to the Huron River and is surrounded by natural areas and recreational facilities. Thousands of bikers use North Main Street to access Huron River Drive, a popular destination for recreational cyclists. The Border-to-Border Trail and the Ann Arbor Rowing Club are frequented by bicyclists and walkers, many of whom are high school students traveling to the rowing club for after school practices. WBWC has been contacted by numerous bicycle commuters who fear for their safety along this stretch of MDOT-controlled roadway due to high speeds and poor infrastructure. Studies have shown that when motorists are traveling at 45 mph, a pedestrian or cyclist has an 85% chance of dying when hit. The safety needs of these users, not a small population in Ann Arbor, were not accounted for when the speed limit was raised to 45mph.
Washtenaw Avenue is another area in Ann Arbor where the 85th percentile method raised the limit in 2008 (http://blog.mlive.com/annarbornews/2008/04/speed_limits_to_go_up.html). Last October a bicyclist was killed there—a young father, on his way home from work. It was dark and rainy. As you know, the 85th percentile speed is determined when conditions are ideal: daylight, no rain. Further, drivers who are slowing for bicyclists are not counted in an 85th percentile speed study. It becomes a vicious cycle, when speed limits are raised according to such a study, fewer non-motorists dare to frequent the area, and it becomes more dangerous for those who do.
We respectfully request that you consider the lives of not only motorists but also non-motorized users when evaluating legislation. And when you evaluate cost-benefit ratios of increasing speed limits, please don’t forget to figure in the health care costs of increased crashes, and the economic (not to mention psychological) blow to families that lose a loved one.
Thank you for considering this testimony.
Peter Houk, WBWC Board Chair on behalf of
The Washtenaw Bicycling and Walking Coalition
Ann Arbor, Michigan
The WBWC's 2018 Ann Arbor Primary Election Candidate Survey Results
July 17, 2018
The WBWC invited each candidate of the Ann Arbor August 7th Primary Election to fill out an online survey. Our goal was to provide a set of questions...