Related information:

Maximum posted speed limits

May 2013

The following table lists the speed limits for various types of roads in the 50 states and the District of Columbia. If a state has different speed limits for commercial trucks, they are listed separately.

In many states, the maximum speed limit that state or local authorities can establish depends on whether the road is a rural or urban interstate, a noninterstate limited-access highway, or another type of road. Limited-access highways are multiple-lane roads with restricted access via exit and entrance ramps, rather than intersections. The limited-access highways that make up the national interstate highway system are divided into urban and rural sections, based on population density figures from the U.S. Census Bureau. The designations may be adjusted by state and local governments to reflect planning and other issues.

Speed limits have traditionally been the responsibility of the states. In the mid-1970s, however, Congress established a national maximum speed limit by withholding highway funds from states that maintained speed limits greater than 55 mph. The requirement was loosened for rural interstates in 1987 and completely repealed in 1995. As of today, 35 states have speed limits of 70 mph or higher on some portion of their roadway systems.

Table
Map: maximum posted daytime speed limits on rural interstates

Maximum posted daytime speed limits on rural interstates

maximum limit may apply only to specified segments of interstate
(hover over map for more detail)

¹In Hawaii, the maximum speed limit is established by county ordinance or by the director of transportation.

²In Kentucky, the speed limit may be increased to 70 mph on specific segments of highway upon the basis of an engineering and traffic investigation. KRS 189.390

³In sections of I-10 and I-20 in West Texas and sections of Highway 45 in Travis County, the speed limit for passenger cars and light trucks is 80 mph. Speed limits may be established not to exceed 85 mph if the highway is originally constructed and designed to accommodate the higher speed and it has been determined by an engineering study to be reasonable and safe. State Highway 130 (portions toll) is operating with a posted limit of 85 mph, effective Oct. 2012.

⁴2013 UT HB 83 expands the portion of roads that may be posted at speed limits that exceed 75 mph to include a portion of Interstate 15 that is between milepost 244 and milepost 24 or between milepost 366 and the Utah-Idaho state line; a portion of Interstate 80 that is between milepost 99 and the Utah-Nevada state line; or a portion of Interstate 84 that is between the Tremonton Interchange and the Utah-Idaho state line. The new limits, reportedly 80 mph, will become effective upon signage.

⁵In Virginia, the posted limit may be as high as 70 mph where indicated by lawfully placed signs, erected subsequent to a traffic engineering study, effective 07/01/10.


	Utah 75; specified segments of road may have posted limits that exceed 75⁴


	Alabama 70


	Alaska 65


	Arizona 75


	Arkansas 70; trucks: 65