Bill Summary – FastDemocracy

Legislative Analysis
                                                                                  Phone: (517) 373-8080
DETERMINING MODIFIED SPEED LIMITS
                                                                                  http://www.house.mi.gov/hfa
House Bill 4012 as reported from committee                                        Analysis available at
Sponsor: Rep. Bradley Slagh                                                       http://www.legislature.mi.gov
Committee: Transportation, Mobility and Infrastructure
Revised 4-11-24
                                                                       (Enacted as Public Act 33 of 2024)
SUMMARY:
          House Bill 4012 would amend the Michigan Vehicle Code to change procedures for setting
          certain speed limits on Michigan highways. 1
          Section 627 of the code establishes Michigan’s “Basic Speed Law,” which generally requires
          that drivers keep to a speed that will allow their vehicle to stop safely under current road
          conditions. Section 627 also provides general speed limits for various types of roads and in the
          state—gravel roads, for example, or roads that are in a business district or mobile home park.
          These constitute a kind of default setting or standard for establishing the speed limit for any
          given stretch of road. For a driver, they are the speed limits that apply when there is no speed
          limit posted (as long as the Basic Speed Law is obeyed).
          Section 628 of the code provides procedures under which the Michigan Department of
          Transportation (MDOT) and county and local road authorities can modify those general speed
          limits to account for local circumstances. This is the section the bill would amend.
          Currently, a modified speed limit under section 628 must be determined by an engineering and
          safety study and by the eighty-fifth percentile speed of free-flowing traffic under ideal
          conditions of a section of highway rounded to the nearest multiple of five miles per hour. (The
          eighty-fifth percentile speed is the speed that 85% of the drivers on a given section of roadway
          are currently driving at or below.)
          The bill would remove the reference to an engineering and safety study and require instead that
          the modified speed limit be determined “in accordance with traffic engineering practices that
          provide an objective analysis of the characteristics of the highway” as well as by the eighty-
          fifth percentile speed on the fastest portion of the segment for which the speed limit is being
          posted. The bill would also require that the speed limit be rounded to either multiple of five
          miles an hour that is within five miles an hour of the eighty-fifth percentile speed.
          The bill would add that a speed limit could be set below the eighty-fifth percentile speed if an
          engineering and safety study demonstrated a situation with hazards to public safety that are not
          reflected by the eighty-fifth percentile speed. However—and as under current law—the speed
          limit could not be set below the fiftieth percentile speed (that is, the speed that half the drivers
          on a given section of roadway are currently driving at or below).
          MCL 257.628
1
    See https://www.michigan.gov/documents/Establishing_Realistic_Speedlimits_85625_7.pdf
House Fiscal Agency                                                                                Page 1 of 2
FISCAL IMPACT:
       The bill would amend section 628 of the Michigan Vehicle Code, which prescribes procedures
       for establishing speed limits on public highways and provides for exceptions to those general
       standards. Specifically, as described above, the bill would provide for the establishment of
       speed limits lower than the general eighty-fifth percentile standard in specified circumstances.
       The bill does not appear to establish new procedures that would materially affect the cost of
       traffic and speed studies and thus would have no direct fiscal impact on the state or local units
       of government.
POSITIONS:
       Representatives of the following organizations testified in support of the bill (6-6-23):
          • Michigan Municipal League
          • League of Michigan Bicyclists
       The following entities indicated support for the bill (6-6-23):
          • City of Ann Arbor
          • Michigan Association of Chiefs of Police
          • Michigan Townships Association
          • Southeast Michigan Council of Governments (SEMCOG)
       A representative of County Road Association of Michigan testified with a neutral position on
       the bill. (6-13-23)
       The Michigan State Police indicated a neutral position on the bill. (6-6-23)
       A representative of ABATE of Michigan testified in opposition to the bill. (6-6-23)
                                                          Legislative Analyst: E. Best
                                                               Fiscal Analyst: William E. Hamilton
■ This analysis was prepared by nonpartisan House Fiscal Agency staff for use by House members in their
deliberations and does not constitute an official statement of legislative intent.
4012House Fiscal Agency                                                 HB 4012 as reported   Page 2 of 2
Statutes affected: 
House Introduced Bill: 257.628
As Passed by the House: 257.628
As Passed by the Senate: 257.628
House Concurred Bill: 257.628
Public Act: 257.628
House Enrolled Bill: 257.628