- The standard limits are 80,000 pounds gross weight, 20,000 pounds on a single axle and 34,000 pounds on a tandem axle group, subject to the bridge formula and tire ratings.
- Standard dimensions are 8 feet 6 inches wide and 14 feet high, and a semitrailer can be up to 59 feet long.
- Loads that go over these limits need an oversize/overweight permit from the Texas Department of Motor Vehicles (TxDMV).
Weight limits
| Measure | Standard limit |
|---|---|
| Gross vehicle weight | 80,000 lbs |
| Single axle | 20,000 lbs |
| Tandem axle group | 34,000 lbs |
| Axle groups generally | Limited by the federal bridge formula, which depends on the number of axles and the distance between them |
| Tires | No more than the tire manufacturer's rated load |
Texas sets these limits in Transportation Code Chapter 621. The federal rules for the Interstate System are in 23 CFR Part 658. Some specific commodities and routes have their own permits or allowances.
Size limits
| Dimension | Standard limit |
|---|---|
| Width | 8 ft 6 in (102 in), not counting certain safety devices such as mirrors |
| Height | 14 ft |
| Semitrailer in a truck-tractor combination | 59 ft |
| Single motor vehicle (straight truck) | 45 ft |
| Truck-tractor | No overall length limit for the tractor itself |
A 14-foot legal height doesn't guarantee clearance under every bridge. Drivers and carriers are responsible for checking posted clearances and permitted routes.
Oversize and overweight permits
Loads that can't be reduced in size or weight, such as heavy equipment, wind turbine parts or prefabricated buildings, can move with an oversize/overweight permit from TxDMV's Motor Carrier Division. Permits set the route, travel times and any escort or flag requirements. Travelling off the permitted route or outside its conditions can void the permit.
Why weight matters in a crash
- Heavier trucks need longer stopping distances, and overloaded trucks put more strain on brakes and tires.
- Weigh-station tickets, bills of lading and scale receipts can show whether a truck was overweight.
- Improperly secured or unbalanced cargo can cause rollovers and spills. The cargo securement rules are in 49 CFR Part 393, Subpart I.
The shipper or the company that loaded the trailer can sometimes share responsibility for a crash. See who can be liable in a Texas truck accident.