Permits valid for five travel days. Must have a permit prior to entering the state.
Michigan permitting system: https://milogintp.michigan.gov/eai/tplogin/authenticate?URL=/
Contact phone number: 1-517-241-8999
Sunrise to sunset. Weekend travel is now being permitted on a trial basis for loads not exceeding 10' wide, 14' in height, and 90' in length. No weekend travel when dimensions are greater. However, overweight only with all dimensions all legal and not exceeding 70' overall length can have continuous travel.
Loads over 12' wide or 90' long are not to move from 7:00 a.m. – 9:00 a.m. and from 3:00 p.m. – 6:00 p.m. in the following counties: Genesee, Ingham, Jackson, Kalamazoo, Kent, Muskegon, Macomb, Oakland, Saginaw, Westenau, Wayne. No travel on major holidays and holiday weekends. Check with the Sammons Permit Office.
Note on Bridge Crossings: Contact Mackinaw Bridge Authority (phone 906-643-7600) 24 hours prior to planned bridge arrival/crossing. The escort will be provided (no charge) for loads exceeding legal weight or 10' wide. The crossing is not allowed when winds exceed 25 miles per hour. Ambassador Bridge (between Detroit and Windsor, Ontario) is now charging $50.00 or more for O/D shipments and may require a one-day notice. They have restricted crossing hours from 10:00 AM to 4:00 PM, Monday through Friday. Ambassador Bridge phone is 313-496-1111.
Width: 8'6" designated highways, 8'0" all other roads
Length: 53' semi-trailer on Interstate and designated highways, 50' maximum on non-designated highways.
Weight: 80,000 Gross Steer Axle – 700 pounds per inch of tire width (15,400 pounds with 11" tires)
Tandem – 34,000 (32,000 on non-designated roads, and 26,000 on second tandem)
Tridem – 42,000 (39,000 on non-designated) Single – 20,000 designated highways (18,000 other roads)
ROUTINE PERMIT LIMITS:
Width: 16' (or 14' during spring thaw restrictions)
Height: 15' Shipper/driver is responsible for finding safe routes when the height exceeds 13'6"
Weight: "Handled on a case-by-case basis." Air or lift axles should be on the ground.
(Note: Exceptions apply during frost law period, see the section below.)
Loads exceeding these dimensions must be applied for as superloads and may take up to ten days to issue once shipper letter, route surveys, etc. are received.
Note: Michigan is very slow on processing superload permits.
Width: Over 12' – 1 escort; over 14' – 2 escorts
Height: Over 14'5" – 1 escort with a high pole; over 15' – 2 escorts and a route survey must be submitted and approved.
Length: Over 90' – 1 escort; over 100' – 2 escorts.
Overhang: Over 14' – 1 escort.
According to the Michigan provision sheet, "Vehicles must have air or lift axles on the ground." According to the permit office, when under a load (even legal weight load), all axles including flip axles must be on the ground.
SEASONAL LOAD RESTRICTIONS:
Usually, from February to April, maximum weights per axle and specific routing may vary. No overweight permits will be issued during the spring weight restriction period. Maximum axle weights may be reduced by up to 35%. A tandem group may be allowed only 26,000 pounds (13,000 pounds per axle), or with two tandem groups, they may allow 26,000 pounds for one group and 32,000 for the other tandem group. Frost Phone: 800-787-8960
SIGNS, FLAGS & LIGHTS:
"Oversize Load" signs required on the front of the vehicle and on the rear of load for any over-dimensional load. An overwidth or overlength vehicle/load requires flags at each corner of the load, with an additional flag at the widest point on each side of the load if it extends beyond the corner flags. When the rear overhang is 4' or more, the extreme rear of the load must have a flag for daytime running, and a red light or lantern at night.