Michigan Truck Bans & Hazmat Routes

Where Michigan keeps trucks out

Detroit's crossings are the story. The Detroit-Windsor Tunnel bans all placarded hazmat and posts a hard ceiling near 12'8" that many box trucks clear only on paper. The Ambassador Bridge reopened to most hazmat on October 29, 2024, so Class 3 flammables and Class 8 corrosives now cross off-peak under escort; only explosives, infectious, and radioactive loads still divert to Blue Water or the truck ferry. No cars-only parkways; through trucks take the I-696 and I-275 beltways.

Key restrictions

• Detroit-Windsor Tunnel: no placarded hazmat at all, and a hard height limit near 12'8" that many box trucks and reefers do not clear.
• Ambassador Bridge now takes Class 3 flammables and Class 8 corrosives off-peak under escort (since Oct 29, 2024); it still bars Class 1 explosives, Class 6.2 infectious, and Class 7 radioactive.
• Blue Water Bridge (Port Huron) bars classes 1, 5, 7, 9 and pyrophoric liquids; Class 1 and 7 loads bound for Canada run on the Detroit-Windsor Truck Ferry.
• No cars-only parkways; through trucks use the I-696 and I-275 beltways around Detroit.

• Parkway / road ban: No cars-only parkways. Detroit posts local truck routes and moves through trucks onto the I-696 and I-275 beltways.
• Hazmat: The Detroit-Windsor Tunnel bans all placarded hazmat and posts a roughly 12'8" height limit. The Ambassador Bridge reopened to most hazmat on October 29, 2024: Class 3 flammables and Class 8 corrosives now cross during off-peak hours under vehicle escort, and only Class 1 explosives, Class 6.2 infectious substances, and Class 7 radioactive material remain restricted. The Blue Water Bridge (I-94/I-69, Port Huron) bars classes 1, 5, 7, 9 and pyrophoric liquids. Loads barred from every bridge use the Detroit-Windsor Truck Ferry.
• Through-truck routes: Detroit and other cities mark truck routes and post weight limits on local streets. Through trucks use the I-696 and I-275 beltways around Detroit. Michigan sets hazmat routing through MDOT; a local truck may leave the route only for the nearest stop.
• Fine: A hazmat placard or over-height violation at a border crossing gets you turned back by the operator and CBP and can draw federal hazmat penalties; local truck-route and weight tickets in Detroit typically run about $100 to $500.

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