Jeff from Colorado writes, “What’s driving you crazy? I am a truck driver. In Colorado we can go to 85,000lbs. But trucks over 80,000 lbs are not allowed on the Interstates. We must stay on secondary roads. This is a STUPID law. Heavy trucks, some with hazardous chemicals, routinely go through towns in school zones and hospital zones. The State trucking associations have for years trying to change this law. Please talk about this as it is unsafe for the people.”
The issue here is that the interstate highway regulations are controlled by the United States Congress, not individual states. But what makes this federal/state weight conundrum even more confusing is the states are still playing a role in what the load limit is in each state on their federal interstate highways. More on that in a second.
There is a federal set of standards that specify the maximum weight that is allowed on federally funded highways, which include the interstates and national network of highways. That way there is a standard set of rules that truck drivers follow that are common across the country. The National Gross Weight limit is set at 80,000 pounds. There are also bridge laws which restrict the spacing and weight of axle groupings to protect bridges from being damaged. The longer and the more axles a truck has, the more weight that it can carry.
In 1991 congress passed the Intermodal Surface Transportation Efficiency Act. That act put a freeze on the load weight limits and truck configurations that were in place in each state back at that time. So the states with more generous load limits before the act was signed are allowed to keep their higher limits after the act took effect, even on interstate and US Highways In the case of Colorado, our interstate weight limit at that time was 80,000 pounds so it has been frozen at that level for the past 27 years. Other states at that same time had a higher weight limit allowed on their interstates, so they have been allowed to continue letting trucks roll down the interstates with loads heavier than 80,000 pounds.
Some of the states that allow higher weight limits on federal interstate highways include Michigan with a theoretical maximum weight of 164,000 pounds depending on the number of axles. Maine has a weight limit of 100,000 pounds while neighboring New Hampshire has a 99,000 pound limit. State laws in New York allow for trucks to carry up to a gross weight of 117,000 pounds. The highest weight limit state is South Dakota with no gross weight limit and no limit on the number of axles you can put on a truck. Agricultural products are common South Dakota with gross weights exceeding 170,000 lbs.
Greg Fulton, President of the Colorado Motor Carriers Association tells me efforts have been made to modify or remove the 1991 freeze but those efforts have been unsuccessful in Congress.
“We believe that it would be in the best interests of all motorists along with businesses in our state if trucks could operate at 85,000 pounds on the Interstate. Those highways are better designed for heavier weights as well as truck traffic and it could reduce excess mileage associated with using alternate routes to the Interstate which would also reduce both energy use and emissions,” Fulton says.
Many truckers like you say the current 80,000 pound weight limit for trucks on interstate highways results in some trucks hauling trailers that are only a bit more than half full. That, they say, creates economic inefficiencies by needing more trucks to deliver lighter loads. There have been attempts by some members of congress to increase the federal weight limit to 91,000 pounds and 97,000 pounds. All bills have failed to be passed.
Of course, the states are always free to keep higher weights in place on state roads that they finance themselves. Colorado allows the higher weight limit of 85,000 pounds on non-interstate highways.
Fulton says in regard to the concern you have about trucks hauling hazardous loads over 80,000 pounds through small towns, “the fact is that carriers transporting hazardous materials are restricted to specific routes for those materials. By no means do I see these shipments being diverted through small towns or locations on these other routes unless they were permitted to do so.”
Fulton tells me the interstate tends to the be the primary route for hazardous materials except during pickup and delivery. So bottom line Jeff, it will take an act of congress to overrule a previous act of congress before the weight limits are increased.
Denver7 traffic anchor Jayson Luber says he has been covering Denver-metro traffic since Ben-Hur was driving a chariot. (We believe the actual number is over 20 years.) He's obsessed with letting viewers know what's happening on their drive and the best way to avoid the problems that spring up. Follow him on Facebook, Twitter or Instagram or listen to his Driving You Crazy podcast on iTunes, Stitcher, Google Play, and Podbean.