18 Wheeler Truck Tires Not Designed For Highway Speeds Over 75 mph

Recent news highlights something that 18 wheeler accident lawyers have known for a long time: higher speed limits for big rigs means more tire blowouts and more accidents. The reason for this comes from an unexpected location: where the rubber meets the road. Truckers who drive at speeds above 75 mph may be violating the speed limit. Not the speed limit on the highway — the speed limit on their tires. According to an AP report, the higher speed limits on some US highways, including highways in the Houston area, may be unsafe for tractor-trailers with standard truck tires. It may come as a surprise that tires have speed limits. They are actually called speed ratings, and have to do with how well a tire holds up under the stress of high-speed driving. A tire is not a load-bearing device. It is more of a container. The weight of the vehicle is actually carried by the air inside the tire. If you watch a car’s tires on the road, you can see that the sidewall at the bottom tends to bulge outward. That is because the weight of vehicle pushes some of the air upward. As the wheel rotates, different parts of the tire are at the bottom, flexing under pressure, then smoothing out as the pressure is released. All this flexing creates heat. Heat damages tires. This is why speed ratings matter. When a trucker drives too fast for the tire, the tire can fail. Why Are Truck Speed Limits So Fast? Most truck tires are rated for 75 mph. Since factors other than speed, such as road conditions, load weight and temperature, can also damage tires, that speed may still be too much for the tire to withstand. So, why do 14 states have speed limits of 75 mph or more? Speed limits are usually based on how fast the majority of drivers think they should drive. If the speed limit is too low, drivers tend to ignore it. That makes a higher limit the safer choice in many cases. This is especially true in states like Texas, where people have to drive long distances. In many cases, the state officials that set the speed limits were unaware of the technical limitations of tires used on 18-wheelers. Each state sets its own speed limits. Tire standards are created by the National Highway Traffic Safety Administration. Why Aren’t Truck Tires Built for Higher Speeds? Since many trucking companies outfit their trucks with devices to limit driving speeds, there is little financial incentive for tire makers to build their products to a higher rating. They feel the market for fast truck tires is too small to cover the cost of changing the design. Tire speed ratings apply to passenger vehicles, too. Car tires have the rating marked on the sidewalls. As an additional safety measure, tires for cars and light trucks must be able to run at 112 mph. Who Is Responsible If a Tire Fails? In Texas, truck drivers are required to know the limits of their rigs. Some drivers are aware of the fact that most truck tires are only rated for 75 mph, and in many cases, trucks have governors to limit their speed. Where such devices are not used, the speed is left completely up to the driver. Unfortunately, some drivers base their decision on the speed limit, not the limitations of their rigs. They may even be unaware that speed ratings exist. Houston 18 wheeler accidents often have tragic consequences. The highways trucks use are also used by thousands of passenger vehicles. The enormous size difference between a car and a tractor-trailer makes serious injury or death a common occurrence. A tire failure often affects drivers beside or directly behind a truck. To protect yourself, avoid driving too close to an 18-wheeler on the highway. Be especially careful if the truck is traveling at speeds of 75 mph or higher. If you, or a loved one, is involved in a collision with a big rig, contact a truck accident attorney who understands how to best protect your rights.