Maryland commercial vehicle weight limits follow the federal Interstate standard of 80,000 lbs gross, 20,000 lbs per single axle, and 34,000 lbs per tandem axle group. The federal bridge formula (23 U.S.C. 127) applies on all routes. Maryland imposes spring weight restrictions on secondary state routes typically March through April. Check SHA for current restricted routes. Oversize and overweight permits are available from MD DOT for loads exceeding standard limits. Verify current road-specific postings with the Maryland DOT before routing heavy loads.
Maryland imposes spring weight restrictions on secondary state routes typically March through April. Check SHA for current restricted routes.
Check current restrictions at MD DOT →The federal bridge formula limits the weight on any group of axles based on the distance between the outermost axles in the group. It applies in Maryland on all routes where federal standards apply.
W = maximum weight in lbs · L = axle spacing in feet · N = number of axles
Maryland SHA issues oversize/overweight permits through the online permit system. Single-trip permits handle most overweight loads. Annual permits available for qualifying recurring operations. Superloads require engineering review and pre-approved route analysis. Loads crossing the Chesapeake Bay Bridge require coordination with MDTA. Baltimore tunnel moves for oversize/overweight require special coordination.
Apply for Maryland OS/OW Permit →On Maryland Interstate highways, the maximum gross vehicle weight is 80,000 lbs — the federal standard. State routes and secondary roads may have lower posted limits. Chesapeake Bay Bridge (US-50) has specific posted weight limits. Overweight permits from SHA are required for loads exceeding standard limits.
The Chesapeake Bay Bridge (US-50/301) has posted weight limits that may differ from standard highway limits. Oversize/overweight vehicles should verify current bridge weight limits with MDTA before routing. High wind conditions also cause bridge closures for high-profile vehicles — check MDTA for current conditions.
No — the Baltimore Harbor Tunnel and Fort McHenry Tunnel prohibit certain HazMat placard categories including Class A explosives and other restricted materials. CDL drivers with restricted HazMat loads must use alternate routes around the tunnels. Verify current tunnel HazMat restrictions with SHA and MDTA before routing through Baltimore.
Yes. Maryland imposes spring weight restrictions on secondary state routes typically from March through April. Interstate highways are not affected. County roads and state secondary routes post reduced limits during the spring thaw period. Check SHA for current restricted routes before routing heavy loads on non-Interstate Maryland roads.
Maryland oversize/overweight permits are issued by the State Highway Administration (SHA) through the online permit portal at roads.maryland.gov. Single-trip permits handle most one-time heavy hauls. Annual permits are available for qualifying recurring operations. Superloads require engineering review. Moves involving the Chesapeake Bay Bridge or Baltimore tunnels require additional coordination.
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Disclaimer
The information on this page is compiled from publicly available government sources and is provided for general informational purposes only. TruckRadar is an independent search engine — we are not affiliated with any government agency and this content does not constitute legal or compliance advice. Regulations change frequently; always verify current requirements directly with the official source before making compliance decisions.
Official source: Maryland MD Department of TransportationLast reviewed: 2026-04