Speed limits in the United States are set by each territory or state. Some states have lower limits for trucks and at night, and occasionally there are minimum speed limits. One of the first speed limits was set in Boston in 1701 (at the time, still a British colony).
The basic speed rule requires drivers adjust speeds to the conditions. This is usually relied upon to regulate proper night speed reductions, if required. Numeric night speed limits, which generally begin 30 minutes after sunset and end 30 minutes before sunrise, are occasionally used. They are used where, in theory, safety problems require a speed lower than what is self-selected by drivers. Some states create arbitrary night speed limits applicable to entire classes of roads.
View the Speed limits in USA:
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 (mph). Some states have lower limits for trucks and at night. Occasionally there are minimum speed limits. Most speed limits are set by state or local statute. However each state allows various subdivisions (counties and municipalities) to set a different, generally lower, limit.
National speed limits in the United States: Speed limit in Alabama, Speed limit in Alaska, Speed limit in Arizona, Speed limit in Arkansas, Speed limit in California, Speed limit in Colorado, Speed limit in Connecticut, Speed limit in Delaware, Speed limit in Florida, Speed limit in Georgia, Speed limit in Hawaii, Speed limit in Idaho, Speed limit in Illinois, Speed limit in Indiana, Speed limit in Iowa, Speed limit in Kansas, Speed limit in Kentucky, Speed limit in Louisiana, Speed limit in Maine, Speed limit in Maryland, Speed limit in Massachusetts, Speed limit in Michigan, Speed limit in Minnesota, Speed limit in Mississippi, Speed limit in Missouri, Speed limit in Montana, Speed limit in Nebraska, Speed limit in Nevada, Speed limit in New Hampshire, Speed limit in New Jersey, Speed limit in New Mexico, Speed limit in New York, Speed limit in North Carolina, Speed limit in North Dakota, Speed limit in Ohio, Speed limit in Oklahoma, Speed limit in Oregon, Speed limit in Pennsylvania, Speed limit in Rhode Island, Speed limit in South Carolina, Speed limit in South Dakota, Speed limit in Tennessee, Speed limit in Texas, Speed limit in Utah, Speed limit in Vermont, Speed limit in Virginia, Speed limit in Washington, Speed limit in West Virginia, Speed limit in Wisconsin, Speed limit in Wyoming and Speed limit in Washington DC.
The highest speed limits in US are generally 70 mph (113 km/h) on the West Coast, 75–80 mph (121–129 km/h) in inland western states, along with Louisiana. 70 mph (113 km/h) is posted in eastern states. A few states, mainly in the Northeast Megalopolis, as well as Puerto Rico and Alaska, have no higher than 65 mph (105 km/h) limits. 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). 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). Portions of the Idaho, Montana, South Dakota, Texas, Utah, and Wyoming road networks have 80 mph (129 km/h) limits. The highest posted speed limit in the entire country can be found in one single stretch of rural freeway in Texas. So there the speed limit is 85 mph (137 km/h).
Some jurisdictions set lower speed limits that are applicable only to large commercial vehicles like heavy trucks and buses. However while they are called “truck speed limits”, they generally do not apply to light trucks.
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).