HB 4522 — Summary (Michigan Vehicle Code, MCL 257.634)
Status and timeline
- Filed March 12, 2025; House bill introduced May 22, 2025 by Rep. William Bruck.
- Reported favorably by House Transportation & Infrastructure (committee report complete 9‑10‑25).
- Passed the Michigan House with immediate effect on September 24, 2025 (Roll Call #224: Yeas 92, Nays 8).
- Referred to the Senate Committee on Transportation and Infrastructure on September 29, 2025.
Purpose / intent
- Modify lane‑use rules in the Michigan Vehicle Code for large trucks, truck tractors, and vehicle–trailer combinations, primarily on freeways, by changing which lanes those vehicles may occupy.
Key provisions
- Definitions: “Freeway” = divided arterial highway with full control of access and grade‑separated crossroads.
- Current law (before change): drivers of a truck with gross weight >10,000 pounds, a truck tractor, or a vehicle–trailer combination must drive only in either of the two lanes farthest to the right.
- Change enacted by HB 4522:
- On freeways with three or more lanes in the same direction, those trucks are prohibited from driving in the lane farthest to the left (i.e., the leftmost lane), except for a reasonable distance when:
- making a left turn (including using a left‑side freeway exit);
- avoiding a special hazard that requires use of another lane for safety; or
- where posted because of a lane closure for construction or repair.
- If construction closes one or more lanes so that only two usable lanes remain, the specified trucks must drive in the rightmost lane except for the same listed exceptions.
- Local preemption: cities, villages, townships, and counties may not enact ordinances on the same subject matter as these subsections.
Who is affected
- Primary: drivers/operators of trucks with gross vehicle weight over 10,000 pounds, truck tractors, and combinations with trailers/semis operating on Michigan freeways.
- Secondary: Michigan Department of Transportation (MDOT) for sign changes and implementation; local governments are preempted from regulating this subject.
- Enforcement: violations are civil infractions under the Vehicle Code.
Fiscal and administrative impacts
- MDOT estimates implementation will require changes to ~120 signs statewide and potential lane closures for installation at an estimated cost of $250,000–$300,000 (excluding costs related to lane closures).
- Net fiscal impact to state and local governments is indeterminate. Civil fines (unknown volume) would fund public/county law libraries and contribute to the Justice System Fund; a $40 justice system assessment applies to civil infraction determinations (except parking violations).
Positions recorded
- Michigan Trucking Association: support (8‑19‑25).
- Michigan Department of Transportation: neutral (7‑29‑25).
Statutory reference
- Amends section 634 of 1949 PA 300 (MCL 257.634).
