Maryland Truck Bans & Hazmat Routes

Where Maryland keeps trucks out

Baltimore is the hazmat chokepoint. Both harbor tunnels, the Fort McHenry (I-95) and the Baltimore Harbor (I-895), ban placarded loads and propane over 10 pounds per container, and an empty cylinder counts the same as a full one (COMAR 11.07.01). Prohibited loads detour the western I-695 Beltway now, because the Key Bridge that used to carry them collapsed in 2024 and stays gone until about 2030. The size plates and signs are posted and enforced by MDTA.

Key restrictions

• Fort McHenry Tunnel (I-95): no placarded hazmat; size limit 14'6" high, 11' wide.
• Baltimore Harbor Tunnel (I-895): no placarded hazmat; size limit 13'6" high, 8' (96 in) wide.
• Propane over 10 lb/container is barred even empty; there is no small-load pass (COMAR 11.07.01).
• Key Bridge is down until about 2030; prohibited hazmat detours the western I-695 Beltway, not the old outer crossing.

• Parkway / road ban: The National Park Service section of the Baltimore-Washington Parkway (MD 295, from the DC line up to about MD 175) bans commercial vehicles; trucks use I-95 or I-295 instead. US Park Police enforce it.
• Hazmat: Both Baltimore harbor tunnels ban placarded hazmat under COMAR 11.07.01. The Fort McHenry Tunnel (I-95) and the Baltimore Harbor Tunnel (I-895) bar bottled propane over 10 lb per container (max 10 containers, empty counts the same as full), bulk gasoline and flammable liquids, explosives, and radioactive material. Prohibited loads must detour on the western section of I-695 (west Baltimore Beltway). The Francis Scott Key Bridge, the old outer-harbor hazmat route, collapsed on 26 March 2024 and is still gone; the rebuild is now pushed to about late 2030, so that detour is the western Beltway, roughly 30 to 35 miles.
• Through-truck routes: STAA rigs run the National Network and MDOT-designated routes. Baltimore and other cities post through-truck bans and weight-limited streets. Stay on the truck route unless you have a local pickup or delivery.
• Fine: Running banned hazmat or an over-size load into a Baltimore tunnel draws an MDTA citation and you get turned around; expect a fine in the hundreds plus liability for any damage. A commercial vehicle on the NPS Baltimore-Washington Parkway draws a US Park Police federal citation.

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