Did you know that in some parts of Texas the speed limits for trucks are as high as 75 or 80 miles per hour? And did you know that in states like Texas where the speed limits are higher, those establishing the speed limits did not consult with the tire industry?
This is important because many truck tires, unlike car tires, are not rated for high speeds. Driving faster than a tire’s rated speed can result in excessive heat that damages the tires, causing blowouts, damage to the truck and cargo, and injuries and deaths.
A recent investigation by the National Highway Traffic Safety Administration (NHTSA) into truck tire failures concluded that operators, rather than tire manufacturers, were at fault for exceeding tires’ speed ratings. Other causes of blowouts include under-inflation, too-heavy loads and road debris.
Congress gave individual states the power to set their own speed limits in the 1990s. However, only the federal government can change federally-mandated tire standards. This means that there is a disconnect between trucks that operate legally at high speeds set by individual states and the safety of the tires those trucks use.
Tire manufacturers would prefer not to take it upon themselves to improve speed ratings for the truck tires they manufacture because they are concerned that trucking companies will not purchase the tires frequently enough to justify the cost of re-engineering.
Interestingly, the American Trucking Association, a trade group, is advocating for government-required speed limiting devices on interstate trucks and would like to see a maximum national truck speed limit of 65 MPH. One study, conducted some years ago, showed that 69 percent of semi-trucks already had governing devices installed. Having a 65 MPH speed limit would mean that trucking companies would not have to deal with the tire safety issue; all truck tires are rated for 65 MPH.
Texas is one of three states that allow trucks to travel 80 MPH or more; the other two are Utah and Wyoming. South Dakota will soon raise its truck speed limit to 80 MPH, making four states that permit trucks to operate at this speed, quite probably on tires that are not rated for more than 75 MPH.
It appears that Texas lawmakers and the state’s Department of Transportation were unaware of the tire rating issue and how it might affect the safety of trucks driven at the high speed limits. Officials in Utah, another state with high legal truck speeds, have said that they were unaware of the tire rating issue when they began discussions about raising the truck speed limit.
Truck tire speed ratings will continue to be an issue as long as states have the authority to set their own speed limits. How the matter will be resolved is unknown.