The maximum speed limit by state ranges from 55 miles per hour (MPH) in Washington, DC, to a high of 85 MPH on some road segments in Texas. Seven states have maximum speed limits of 80 MPH, while nine states plus the District of Columbia have speed limits of 65 MPH or less. The most common maximum speed limit for light-duty vehicles across the United States is 70 MPH.
Note: Some of these maximum limits are for specified segments of road only. Many states have different maximum speed limits for heavy trucks.
Source: Insurance Institute for Highway Safety, Highway Loss Data Institute, "Speed Limits," August 2020.