DOT Weight and Size Limit Regulations

Question 1

What is the maximum gross vehicle weight (GVW) allowed on the Interstate highway system without a special permit?

Accepted Answer

80,000 lbs

Answer

Federal law (23 USC 127) limits gross vehicle weight on Interstate highways to 80,000 pounds absent a special overweight permit.

Question 2

What is the federal maximum single axle weight limit on Interstate highways?

Accepted Answer

20,000 lbs

Answer

23 USC 127 establishes a maximum single axle weight of 20,000 pounds on the Interstate highway system.

Question 3

What is the federal maximum tandem axle weight limit on the Interstate highway system?

Accepted Answer

34,000 lbs

Answer

Federal law caps tandem axle weight at 34,000 pounds; tandem axles are typically defined as two axles spaced 40 inches or less apart.

Question 4

What is the maximum vehicle width permitted on federal-aid highways under federal regulations?

Accepted Answer

102 inches

Answer

Federal regulations allow a maximum vehicle body width of 102 inches (8.5 feet) on federal-aid highways, not counting safety devices.

Question 5

Bridge Formula B is primarily used by DOT inspectors to:

Accepted Answer

Calculate maximum allowable axle-group weight based on axle spacing

Answer

Bridge Formula B limits the maximum weight on any group of two or more consecutive axles based on the distance between them, protecting bridges from overload.

DOT Inspector Certification Practice Test

DOT Inspector Certification Practice Test

DOT Weight and Size Limit Regulations