Speed limits in the United States

Speed limits in the United States are set by each state or territory. Highway speed limits can range from an urban low of 35 mph (56 km/h) to a rural high of 85 mph (137 km/h). Speed limits are typically posted in increments of five miles per hour (8 km/h). Some states have lower limits for trucks and at night, and occasionally there are minimum speed limits. Most speed limits are set by state or local statute, although each state allows various subdivisions (counties and municipalities) to set a different, generally lower, limit.

The highest speed limits are generally 70 mph (113 km/h) on the West Coast and the inland eastern states, 75–80 mph (121–129 km/h) in inland western states, along with Louisiana, and 65–75 mph (105–121 km/h) on the Eastern Seaboard. Alaska, Connecticut, Delaware, Massachusetts, New Jersey, New York, Puerto Rico, Rhode Island, and Vermont have a maximum limit of 65 mph (105 km/h), and Hawaii has a maximum limit of 60 mph (97 km/h). Washington, D.C. and the U.S. Virgin Islands have a maximum speed limit of 55 mph (89 km/h), and Guam and the Samoa have speed limits of 45 mph (72 km/h). Unusual for a state east of the Mississippi, much of I-95 in Maine north of Bangor allows up to 75 mph (121 km/h). Although Nevada law has allowed speed limits up to 80 mph (129 km/h) since October 2015, no 80 mph (129 km/h) limit had been posted in Nevada as of August 2016, and it stays pending. Portions of the Idaho, Montana, South Dakota, Texas, Utah, and Wyoming road networks have 80 mph (129 km/h) posted limits. The highest posted speed limit in the entire country can be found in one single stretch of rural freeway in Texas, and it is 85 mph (137 km/h).

For 13 years (January 1974–April 1987), federal law prohibited speed limits above 55 mph (89 km/h). From April 1987 through December 8, 1995, an amended federal law prohibited speed limits above 65 mph (105 km/h).

This table contains the most usual posted daytime speed limits, in miles per hour, on typical roads in each category. The values shown are not necessarily the fastest or slowest. They usually indicate, but not always, statutory speed limits. Some states and territories have lower truck speed limits applicable to heavy trucks. If present, they are usually only on freeways or other high-speed roadways. Nevada and Washington allow for speeds up to 80 and 75 miles per hour (129 and 121 km/h) respectively, but the highest posted signs are 75 and 70 miles per hour (121 and 113 km/h) respectively. Mississippi allows speeds up to 80 mph (130 km/h) on toll roads, but no such roads exist. Oklahoma removed the maximum speed of 75 from its laws, though no road been posted higher than 75.

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