The states with the highest speed limits in the United States

Celeste Polidori
August 22, 2025

From Texas to Wyoming, these are some of the states with the highest speed limits in the U.S.

Speed limits are established with one main goal: to ensure safety on the roads. These mandatory limits must be respected by all drivers; however, they vary from state to state. Although there was once a national speed limit across the United States, over time, and with changes in road infrastructure, states were given the authority to set their own speed limits.

While the law requires every driver to maintain a safe speed that does not pose a risk, the differences between states can be significant. From Texas to Wyoming, these are some of the states with the highest speed limits in the U.S., based on data shared by the website SlashGear.

The 5 States with the highest speed limits in the United States

1. Texas

Texas is the second-largest state in the U.S. and has nearly 80,000 miles of expansive highways. Due to its long stretches of road, the average speed limit in the state is 78 miles per hour (mph); however, in certain areas, it can reach up to 85 mph, the highest in the country.

Although driving at these speeds is legal in some zones, it does not necessarily mean it is completely safe. In 2022, 4,408 people lost their lives in car accidents in Texas, according to data from SlashGear.

2. South Dakota

South Dakota has an average speed limit of 77 mph, five mph higher than neighboring North Dakota and just one mph below Texas. Much of the state lies within the Great Plains region, providing vast stretches of flat terrain. These conditions make it easy for drivers to reach the 77 mph allowed by state law.

3. Idaho

Like South Dakota, Idaho has an average speed limit of 77 mph. Its long highways span landscapes ranging from rivers to the Rocky Mountains, making high-speed driving more feasible. However, it’s essential to remember that safety should always be the top priority. Just because a high limit is permitted doesn’t mean it should be reached at all times.

4. Wyoming

Wyoming ranks fourth on the list. With portions of both the Rocky Mountains and the Great Plains within its borders, the state features expansive highways through vast and open terrain. The average speed limit in Wyoming is 75 mph, just two mph below those of South Dakota and Idaho.

5. Utah

The average speed limit in Utah is also 75 mph. Many of the state’s paved roads traverse challenging terrain with notable efficiency, making high-speed driving relatively safe. However, even in Utah’s wide desert landscapes it’s important to remember that safety depends on many factors, including vehicle condition, such as its fiberglass and steel structure, and its gasoline-powered operation.