Speed Limits

In January of 2017, the Governor signed into law several changes to how speed limits are set in Michigan. The changes to the Michigan Vehicle Code are outlined in Michigan Compiled Laws (MCL) 257.627 through 257.628. What do these changes in the law mean to us in Walker?

If you traveled around the state this summer you probably saw a few stretches of interstate where the speed limit went from 70 miles per hour to 75 miles per hour (mph). The new law requires the Michigan Department of Transportation (MDOT) to raise the upper threshold from 70 to 75 on at least 600 miles of limited access freeway. The implementation of this requirement began almost immediately but must be completed by January of 2018.

We may also see some roads with the "M" designation get increased. The law requires MDOT to increase the speed limit from 55 to 65 on at least 900 miles of state trunkline. While we don't expect any changes in Walker you could see increases on roads like M-37 (Alpine Avenue) or M-45 (Lake Michigan Drive) north and west of our city limits.

On the local level the new law firms up restrictions on how cities set speed limits within their municipal boundaries. Loopholes from the previous 2011 update have been minimized and the 2017 version of the law is focused on having consistent rules across the state. When we look at a speed limit we have two ways of setting that speed limit. First, we can use a method called the Vehicle Access Point (VAP) method. In this approach, we count the number of driveways along a ½ mile segment. If there are 60 or more driveways and intersections we can set that speed at 25 mph. The VAP speed limits are further detailed below:

Access PointsSpeed Limits
60 or more25 mph
50 to 5930 mph
45 to 4935 mph
40 to 4440 mph
30 to 3945 mph

The second method we have to set speed limits is based on the 85th percentile speed of free-flow traffic. The 85th Percentile Speed is the speed that 85% of vehicles do not exceed. Another way of looking at this is that only 15% of vehicles go faster than this speed, and 85% go at or below this speed. The state believes that this helps to minimize crashes and promote a more uniform traffic flow along a corridor. Many professional traffic engineers also believe that using the 85th percentile speed to set speed limits is the safest way to set-top speed expectations.

If you are thinking of requesting a speed study along your road please keep these new rules in mind. Often when a speed study is performed the calculated 85th percentile speed can result in increases to that limit. It's a pleasant surprise when a lower limit is justified but this is a rare event. Remember that the city's hands are tied when it comes to flexibility. If we study a roadway we must come into compliance with the law. In fact, the law is written to allow MDOT or the Michigan State Police to actually step in and raise local speed limits if they believe that the community is not in compliance with the law.

Using these two criteria to set speed limits can often raise speed limits above resident expectations. Unfortunately, this is the law and we must use these regulations when updating speed limits in order to have enforceable limits. One common misconception to remember is that drivers are not always afforded a 10 mph buffer to exceed the posted speeds before getting a ticket. If you are traveling above the posted speed you are "speeding" and you could receive a ticket for any speed in excess of the limit.

The best advice we can provide to our residents is to slow down and plan extra time in their travels. Please pay attention to yellow advisory signs that might suggest a curve or limited sight distance. Also, enter roundabouts and intersections at safe speeds. And lookout for the increasing number of pedestrians we have along our busy corridors and near our schools. Thank you and drive safely!