What is the maximum weight limit for a tractor-trailer combination on interstate highways?

The correct maximum weight limit for a tractor-trailer combination on interstate highways is 80,000 pounds. This limit is established by federal regulations, specifically the Federal-Aid Highway Act, which is designed to ensure safety and protect the infrastructure of roads and bridges. This weight restriction applies to the total weight of the vehicle and its cargo.

Authority on the matter comes from the need to prevent excessive wear and damage to highways and bridges, which can occur if vehicles exceed this weight. The 80,000-pound limit includes the weight of the tractor, trailer, and the cargo being transported. This regulation is enforced to maintain safety on the highways for all vehicles, as well as to comply with engineering standards for road construction and maintenance.

Weights beyond this limit, such as 90,000 pounds or 100,000 pounds, would pose significant risks to highway infrastructure and roadway safety, leading to stricter enforcement and potential penalties for violations. Additionally, individual states may have special permits for heavier vehicles in certain situations, but the general guideline for interstate travel remains capped at 80,000 pounds.