Texas Speed Zone Limits and Studies

National Driver Safety Services. Approval # - C1635
Course provided by: IDriveSafely.com

Call us: 1-800-990-2813

Texas Speed Zones & Safety Precautions


Have you ever thought about how and why lawmakers set a certain speed limit on a particular road? The Texas Department of Transportation (DoT) has outlined their entire process for setting speed zones, explaining just how they conclude how fast or slow you should be allowed to drive!

Both setting and following speed limits are crucial when it comes to keeping drivers safe, while still getting them to their destinations as quickly as possible. The numbers on those signs posted at the side of the road aren’t arbitrary – they have been carefully calculated to allow you to travel at a reasonable speed without endangering your fellow commuters. Read on to find out just how lawmakers come up with these numbers, and how they’re designed to keep you protected.

Setting Speed Zones

According to the DoT, speed zones are set by the 85th percentile of drivers’ speeds. What exactly does this mean? The process is actually quite simple. A random speed check is conducted by using any number of radar devices on free-flowing traffic. The researchers will then use a conglomerate of the observed speeds, and calculate the 85th percentile of that total. In accordance with DoT regulations, the transition from one speed zone to another will never exceed a 15 MPH difference – any change greater than this would likely be too quick for a driver to accommodate in time.

The only exception to this occurs in school zones, where child safety is of the utmost importance, and in that case, the same transition rules apply.

Why Are Speed Zones Important?

Determining a reasonable speed limit, both minimum and maximum, is incredibly important for driver safety. Contrary to popular belief, lawmakers do not want to set a lower speed limit if it isn’t warranted. Setting a speed below what is considered “reasonable” will actually INCREASE the amount of crashes. Drivers who observe what they deem to be too low are limit are more likely to disregard any signs posted at all, and drive faster than what is necessary. Therefore, the DoT has intentionally set speed ranges to accommodate reasonable slower and faster speeds, without endangering anyone.

Speed zones are also set based upon location. If a school or park is nearby, the speed zone will be much lower than that set for an interstate highway, or a little-traveled country road. The type of terrain, nearby population, physical landscape, and wildlife population are all taken into account when determining safe speeds for travel. Dirt roads pose more danger than paved ones, especially when wet or muddy, and a neighborhood known for sharp turns or curves will require a slower speed than a road that stays straight for miles.

Other Safety Precautions

To alert drivers to a significant change in speed, lawmakers have installed various traffic signals and devices along Texas roads. These include flashing lights, road signs, changes in pavement markings, and other tactics.

Driving for the Weather

Regardless of posted speed limits, it’s important to never drive faster than current weather and road conditions allow. Just because the sign allows you to drive at 75 MPH doesn’t mean it’s a smart choice during a heavy rainstorm! Safety begins with making smart, common-sense choices. If a flash-flood occurs, or a sudden windstorm whips up, slow your speed and drive cautiously until the weather subsides. And if your abilities or vision become too impaired, pull over to a safe location and wait it out.


More Useful Articles:

Start Now