Driving laws are set at the state level in the U.S. The federal government only influences traffic laws in each state by tying funding to some driving law standards. As a result, speed limits vary widely across the country.
Generally, most states in the easy set the speed limit maximum on highways is 70 mph and 75 mph in the western states. In the northeast, speed limits are slightly lower at 65 mph. There are 3 states with a maximum speed limit of 80 mph – Idaho, Utah, and Wyoming. All three of these states have large stretches of wide open highway where speeds of up to 80 mph are safe and reasonable.
In Texas speed limits are set at the county level. This results in fairly arbitrary speed limits from county to county and consequently Texas has highest highway speed limit in the country. For a short 40 mile stretch of State Highway 130 between San Antonio and Austin, you can legal drive 85 mph (137 kilometers per hour). The one-way toll is over $6.00. Because people tend to go 5-10 mph above the speed limit, the flow of traffic on SH130 regularly reaches 90-95 miles per hour. Accidents at these speeds are rarely survivable.
Texas also has several areas of 80 mph highways in the western portion of the state and 75 mph speed limit throughout most of the state.
The lowest highway speed in the country is Hawaii with a maximum highway speed limit of only 60 mph. Hawaii’s dense population and limited highway system contribute to the low maximum speed limit. Most states’ speed limits are contingent on weather and driving conditions. So the legal speed limit may be lower than posted speed.
The U.S. has some very high speed limits but the highest speed limits in the world are in Europe. Most of Europe’s max speed is 130 kilometers per hour which is equal to approximately 80 mph. 130 kph is the max speed in Spain, Italy, Austria, Czech Republic, Slovakia, Ukraine, and Russia among others. Both Bulgaria and Poland have a maximum highway speed limit of 140 kph (87 mph).
The fastest highway speed limit in the world is in Germany on the Autobahn. On some sections of the Autobahn outside of major cities the speed limit is unlimited. You may legally drive as fast as you want. While uncommon, some cars travel on the German highway at speeds of over 200 mph. Strict laws regarding passing on the correct side and distracted driving help to keep drivers safe while traveling on the Autobahn at these high speeds.