Mackinac Bridge Authority

Spanning the Straits of Mackinac since 1957

Rules & Regulations


  • Maximum speed limit is 45 mph.
  • No U-turns.
  • No stopping on the Mackinac Bridge.
  • In the event of a flat tire or motor failure, please remain in your vehicle. Bridge personnel on duty will investigate and assist.
  • Use four-way flashers while vehicle is disabled.

Truck Regulations

  • Travel in right lane – no passing.
  • 500-foot spacing – no tailgating.
  • Use four-way flashers.
  • Maximum speed is 20 mph.
  • Rules Enforced from toll plaza to Jamet Street exit.
  • Trucks with a gross load of over 40 tons must request escort prior to crossing.
  • Maximum allowable vehicle weight is 72 tons.

Placarded Loads

  • Transportation of flammable liquids, liquid gases, explosives and other placarded loads requires an escort by bridge personnel. Persons transporting these loads must call Bridge Services at 906-643-7600 for escort.

Oversized Vehicles

  • Oversized vehicles must call 24 hours in advance to arrange a bridge escort.

Other restrictions may be in effect due to weather conditions or construction projects.
Please tune to 530 or 1610 am radio while in the Straits area.