Driving on Houston’s highways is one of the most stressful experiences in our otherwise lovely city—we know it all too well, and so do you. Aggressive lane changes, impatient not-so-neighborly drivers…and then there’s Texas’s, umm, generous speed limits. With some roadways reaching a maximum limit of 85 mph, the Lone Star State holds the highest speed limits in the country. But why exactly is it permissible to drive so fast here, especially when the risk of accidents increases with every mile per hour?

The answer begins with how state authorities determine speed limits. Unlike in some states that have lower limits to err on the side of caution and impose blanket speed limits across the state, the Texas Department of Transportation (TxDOT) relies on traffic and engineering studies to determine speeds for each roadway. By collecting data on traffic patterns, road conditions, and driver behavior, officials claim to gain a deeper understanding of how people typically drive on specific highways and identify potential safety concerns. TxDOT also takes into account factors such as road design, traffic volume, and accident history: highways with more lanes, wider shoulders, and better visibility may accommodate higher speeds, while areas with frequent accidents or narrow roads may need lower limits.

But the primary measure TxDOT uses is a principle known as the 85th percentile speed, which essentially sets limits based on how fast the majority of motorists are already traveling. Yes, you read that right. This rule gained popularity in the 1960s and is based off the Solomon Curve, which illustrates the relationship between vehicle speed and the number of accidents, finding that crash risk is minimized if the limit is set at the speed that 85 percent of drivers are already traveling.

The idea behind the 85th percentile speed rule is to set limits that align with the behavior of the majority of drivers, in the hopes of avoiding frustration and noncompliance. If 85 percent of drivers are cruising down I-45 at 75 mph, that becomes the basis for setting the official speed limit. So…Texas speed limits are high because Texans drive fast? It feels like chicken-and-the-egg territory, but it’s a method grounded in the belief that when people drive at a speed that feels natural to them, roadways tend to function more smoothly—at least in theory.

The high speed limits don’t come without criticism. Some argue that while drivers may feel comfortable pushing 80 mph, comfort doesn’t always equal safety. And let’s face it, on Houston highways, we’re talking more like 90. Studies show that as speeds increase, so does the severity of crashes. In fact, a simple 10 mph jump can significantly raise the risk of fatalities, a sobering reality in a state where fatal car crashes remain an ongoing concern.

Houston has seen a troubling rise in traffic-related deaths. Pedestrian fatalities in particular have surged, sparking debates about whether setting speed limits based on driver behavior overlooks the safety of those who aren’t behind the wheel. It’s not just about cars and trucks. Cyclists, motorcyclists, and pedestrians all share the road—at far greater risk when speeds soar.

Local governments have the authority to lower speed limits within city boundaries, and some Houston-area neighborhoods have taken steps to do so. School zones, residential streets, and densely populated areas often have lower limits, as officials attempt to strike a balance between the convenience of fast travel and the safety of their communities. However, these adjustments don’t go far enough to address the systemic issues posed by high-speed highways cutting through urban areas.

At the end of the day, Texas’s love affair with speed reflects a broader cultural mindset—one that values personal freedom and the open road. But as the state’s population swells and its urban centers become denser, the question remains: how fast is too fast? In Houston, where the highways are both a necessity and a nightmare, that’s a question drivers will likely continue to wrestle with, one lane change at a time.