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Weight limitUnited States

An introduction to the traffic rules and road signs of United States. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.

Traffic signs
Traffic rules
United States

36. Weight limit

A weight limit prohibits vehicles or vehicle combinations whose mass exceeds the value shown from entering or passing a road section, bridge, tunnel or other structure. Depending on local law, the restriction may concern the vehicle’s actual loaded mass, maximum authorised mass or load on an individual axle.

Drivers must know which type of mass the sign refers to and must include the vehicle, passengers, cargo and any trailer where required. A vehicle that exceeds the limit must use another suitable route.

Road signs for Mississippi routes 444 and 32, including a weight restriction. (Mississippi, United States)
Wikimedia.org • formulanone • CC BY-SA
Does every weight-limit sign measure the same kind of vehicle weight in the United States?

No. US weight-limit signs can restrict gross vehicle weight, weight per axle or a class of vehicle. Check the actual units and sign text, and the applicable state or local rule for a particular bridge or road.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant regulatory/warning/guide, marking and signal provisions

Do cargo and trailers matter for a posted weight restriction in the United States?

Yes, whenever the rule is based on actual loaded mass or the total mass of a combination. Cargo, passengers and the trailer affect that figure; weight on individual axles may be limited separately. If the sign instead uses authorised maximum mass, an empty vehicle may still be prohibited.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant regulatory/warning/guide, marking and signal provisions

What should you do if your vehicle exceeds a bridge weight limit in the United States?

Do not drive onto the bridge. Follow the signed alternative route and check the vehicle’s gross and axle loads as applicable. A general heavy-vehicle permit does not automatically authorise crossing every restricted bridge.

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 December2025 — relevant regulatory/warning/guide, marking and signal provisions

1 United States 2 Motorway 3 Expressway 4 Speed limit 5 Minimum speed 6 Advisory speed 7 Bike path 8 Pedestrian warning 9 Tunnel 10 Bridge 11 Speed bump 12 Toll road 13 One-way traffic 14 Slope 15 Bus lane 16 Bus stop 17 Dead end 18 Stop sign 19 Give way 20 Roundabout 21 Road narrowing 22 Pedestrian crossing 23 Railway crossing 24 Mandatory direction 25 Turn prohibition 26 School area 27 Crossing animals 28 Slippery road 29 Rockfall 30 Aircraft 31 Curve 32 Chevron 33 Wrong-way driving 34 Roadworks 35 Height limit 36 Weight limit 37 Radar speed sign 38 Selective barriers 39 Traffic lights 40 Traffic lights warning 41 Pedestrian lights 42 Road markings 43 Bike box 44 Speed feedback 45 Driving licence 46 Traffic mirror 47 Emergency telephone 48 Cycling route 49 Parking 50 No parking 51 No stopping 52 Parallel parking 53 Park and ride 54 Kiss and ride 55 Disabled parking 56 Traffic management 57 Reversing 58 U-turn 59 Carpool 60 Detour 61 Uncontrolled crossroad 62 Ramp 63 Exit 64 Horse riding 65 Emergency exit 66 Runaway truck ramp 67 Oversize load 68 City limit 69 Tourist attraction 70 Horn 71 Axle weight limit 72 Licence plate 73 Charging station 74 Flooding 75 Dip 76 Horse 77 Local traffic 78 Pedestrian 79 Cyclist 80 Motorcycle 81 Truck 82 Bus 83 Police 84 Ambulance 85 Police signals 86 Gravel road 87 Pothole 88 Median strip 89 Public property 90 Path 91 Particulates 92 Air pollution 93 Interchange 94 Rush hour 95 Filling station 96 Road code 97 Two-way traffic 98 Passing lane 99 Street gutter 100 Road debris ...