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 The requirement was loosened for rural interstates in 1987 and completely repealed in 1995.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,
have speed limits of 70 mph or higher on some portion of their roadway systems.
Maximum posted daytime speed limits on rural interstates
maximum limit may apply only to specified segments of interstate
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