Transportation

HB 4391 expands Michigan's vehicle code to allow law enforcement to test for intoxication using other bodily fluids beyond blood or breath, such as urine or saliva. It directly affects drivers suspected of operating a vehicle while impaired, updating sections 625a, 625c, and 625g of the 1949 Michigan Vehicle Code (MCL 257.625a et seq.). The bill amends existing testing methods to include these additional fluids, providing more flexibility for officers during DUI investigations. The bill passed the Michigan House on July 17, 2025, with immediate effect.

HB 4426 amends Michigan's Motor Carrier Safety Act (MCL 480.12d) to set a minimum age of 21 for drivers transporting hazardous materials requiring placards under federal rules. It maintains the existing 18-year-old minimum for most commercial driving but specifically raises the age requirement for hazardous materials transport. The bill does not change medical waiver or grandfathered driver provisions. This change directly affects commercial drivers operating in Michigan who transport hazardous materials requiring placards.

HB 4203 amends Michigan's Vehicle Code to revise exemptions for tow trucks, wreckers, and road service vehicles from seasonal weight restrictions on state highways. The bill allows these vehicles to operate during restricted periods (typically winter months) when responding to emergencies or providing essential roadside assistance. This change directly affects towing and road service companies by permitting them to operate under weight limits they previously could not during certain seasons. The amendment applies specifically to vehicles performing emergency response or required road service functions.

HB 4343 exempts certain commercial trucks assisting in a declared state of emergency from Michigan's frost laws, which typically restrict truck operations during freezing conditions. This means trucks providing emergency response services (like transporting supplies or personnel) will not face traffic violations for operating during frost conditions when supporting emergency efforts. The bill amends Michigan's Vehicle Code (MCL 257.722) to create this specific exception for emergency assistance vehicles. It directly affects commercial truck operators and emergency management agencies during declared emergencies.

HB 4344 removes driving hour limits for commercial motor vehicle drivers during declared state emergencies. It specifically exempts drivers traveling to assist with or directly helping during disasters from federal hours-of-service rules (49 CFR part 395) under Michigan's Emergency Management Act. This change directly affects commercial drivers transporting goods or people in support of emergency response efforts when a state of emergency is active.