The United States has no national speed limit: each state sets its own. Maximum posted limits on rural interstates run from 60 mph in Hawaii to 80 mph in several western and plains states, and one Texas road is posted at 85 mph (about 137 km/h). Speed cameras are a state and city matter, so they are common in some places and prohibited in others.
| Road type | Cars |
|---|---|
| Rural interstates | 60 to 80 mph (85 mph on one Texas road) |
| Urban interstates | 55 to 80 mph |
| Other limited-access roads | 50 to 75 mph |
| Other roads | 45 to 75 mph (25 mph in Washington DC) |
| City streets, examples | 25 mph California, 30 mph Texas, unless posted |
What are the speed limits in the USA?
Speed limits in the USA are set by state law and by local authorities, and the sign on the road is the number that counts. The federal national maximum speed limit was repealed in 1995, which left the decision with the states.
According to the Insurance Institute for Highway Safety (IIHS), the highest posted limit in the country is 85 mph on State Highway 130 in Texas. The maximum is 80 mph on rural interstates in Montana, Nevada, North Dakota and South Dakota, and on specified segments in Idaho, Oklahoma, Utah and Wyoming. Hawaii has the lowest maximum on rural interstates, at 60 mph.
City limits vary as well. California sets 25 mph in business and residence districts and near schools when children are present, unless a different limit applies. Texas sets 30 mph on most urban streets, and 70 mph on numbered highways outside urban districts, unless posted otherwise. Trucks have lower limits in some states, including California.
What kinds of speed cameras does the USA use?
The USA uses automated speed cameras under state and local rules, and state law decides when, where and how they can operate. According to the Governors Highway Safety Association (GHSA), last updated in October 2025, 19 states and Washington DC have laws allowing speed cameras, and 10 states have laws prohibiting them. GHSA also notes that some localities operate cameras even where the state neither permits nor prohibits them.
Many laws limit cameras to specific places. Colorado lists school zones, residential neighbourhoods and active construction zones. Connecticut lists work zones, school zones and pedestrian safety zones. Cameras record the vehicle, and GHSA says citations are mailed to the owner.
Are speed camera apps legal in the USA?
We found no specific federal or state rule on apps that warn about known camera locations, so check locally. Rules on radar detectors do exist. Federal rule 49 CFR 392.71 says no driver may use a radar detector in a commercial motor vehicle. Virginia Code section 46.2-1079 makes it unlawful to drive with a device that detects police speed measurement, and Washington DC regulates radar detectors and jammers under 18 DCMR 736, which bars their sale and their use or possession in a vehicle. Ghost does not detect radar. Checked on 30 October 2026.
What are the rules on using a phone while driving?
Phone rules differ by state, and GHSA counted 33 states, plus Washington DC, that ban hand-held use for all drivers. California Vehicle Code section 23123.5 lets you operate a phone by hand only if it is mounted and the action takes a single swipe or tap.
What should visiting drivers know?
- Limits are posted in mph. To compare, 65 mph is about 105 km/h.
- The limit can change at a state line, so read the first sign after you cross.
- Montana posts different day and night limits on some roads, 75 mph by day and 70 mph at night on other limited-access roads.
- School and work zones often carry lower limits and may have their own camera rules.
Driving north? See our guide to Canada, where limits are in km/h.
