Federal Restrictions on Carrying Capacity

Originally published in the June 2015 edition of Tech Trends (e-newsletter and as an article within NTEA News), this article is also available to you below as an employee of an NTEA member company.

NTEA’s Technical Services Department is receiving questions about maximum carrying capacity for trucks. With summer highway construction on the horizon, companies are looking to maximize the productivity of their dump trucks and other specialized truck bodies. One area of confusion is that Federal Bridge Formula weight laws can restrict total payload before a truck reaches its GVWR. 

Helpful Tips

• The Federal Bridge Formula is developed around the construction capacity of bridges and roadways in the interstate and federal highway system. As most trucks will drive on a federal highway at least once, it is important for them to comply with these weight restrictions.
• For any vehicle on the federal highway system, total allowable weight is based on two key factors: total number of axles on the vehicle, and distance between axle groups and the first and last axle.
• Many times, the GVWR of a three-axle dump truck is higher than the Federal Bridge Formula allows. The Formula allows for more weight by having the front and rear axles spaced as far apart as possible (difficult with the 40’ straight truck length limit in most states) or by adding lift axles.

​​Additional resource available from the NTEA

Tech Connections articles

• Weight Laws and the Federal Bridge Formula: How is Payload Affected?
• Resources for Performing a Weight Distribution and Payload Analysis

 

Are you faced with technical or engineering challenges?
Contact the Technical and Engineering Hotline at (800) 441-6832 for individual attention on varied topics such as Federal Excise Tax, truck certification and labeling, vehicle compliance and truck spec’ing. The Hotline is available Monday-Friday, 8am-5pm (EST). Members can contact the Association as frequently as needed.