What are the speed limits on US interstates? Highest and lowest limits by state

Speed limits on US interstates are set by each state, so there is no single answer. Maximum limits on rural interstates run from 60 mph (97 km/h) in Hawaii to 80 mph (129 km/h) in eight western and plains states and on parts of two Texas interstates, while urban interstates range from 55 mph to 80 mph. The table below shows every state as listed by the Insurance Institute for Highway Safety (IIHS) in November 2026.

What is the speed limit on interstates in the US?

The speed limit on a US interstate is whatever the state has set and posted, and 70 mph is the most common maximum on rural stretches. Twenty states use it as their standard rural figure. Remember that these are maximums. A state or local agency can post a lower limit on any section, so the sign beside you can be below the number in the table.

Grouped by the highest rural interstate limit a state lists, the map looks like this:

• 80 mph or more: Idaho, Montana, Nevada, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming.
• 75 mph: Arizona, Arkansas, Colorado, Kansas, Louisiana, Maine, Michigan, Missouri, Nebraska, New Mexico and Washington.
• 70 mph: Alabama, California, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Minnesota, Mississippi, New Hampshire, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia and Wisconsin.
• 65 mph: Alaska, Connecticut, Delaware, Massachusetts, New Jersey, New York, Rhode Island and Vermont.
• 60 mph: Hawaii.

Several of those top figures apply only to selected roads. Idaho, Oklahoma, Utah, Wyoming, Kentucky, New Hampshire, Michigan, Oregon and Washington all list a higher limit for specified segments only, so the usual number on those interstates is the lower one in the table.

Is the speed limit 65 or 70 on the interstate?

It depends on the state and on the section of road. New York and New Jersey both list 65 mph for rural interstates, while neighboring Pennsylvania lists 70 mph. Connecticut and Delaware also list 65 mph, then drop to 55 mph on urban interstates.

Which state has the highest interstate speed limit?

The highest interstate speed limit in the US is 80 mph, and you will find it in eight states plus parts of Texas. Montana, Nevada, North Dakota and South Dakota list 80 mph for rural interstates generally. Idaho, Utah and Wyoming post it on specified segments, and Oklahoma may post it on portions of its turnpike.

North Dakota is the newest member of this group. A law signed in May 2025 raised its interstate limit to 80 mph from August 1, 2025, and at the same time, stretches near Dickinson, Grand Forks, Jamestown and Valley City were cut from 75 mph to 70 mph. South Dakota is the only state that lists 80 mph for both rural and urban interstates in its general figure.

Is any interstate posted at 85 mph?

No, the 85 mph limit in Texas is on State Highway 130, which is not an interstate. Texas law allows up to 80 mph on parts of Interstate 10 and Interstate 20 in a named list of West Texas and Hill Country counties. Our guide to the highest speed limit in the US covers that road in detail.

Which state has the lowest interstate speed limit?

Hawaii has the lowest maximum interstate limit of any state, at 60 mph on both rural and urban interstates. In Hawaii the maximum is set by county ordinance or by the director of transportation.

On urban interstates the lowest figure in the IIHS table is 55 mph, and it applies in more places than you might expect:

• Northeast: Connecticut, Delaware, New Jersey, Rhode Island and Vermont.
• Midwest and South: Illinois, Indiana and West Virginia.
• West: Alaska and Oregon.
• Washington, DC: 55 mph on its urban interstates, and 25 mph on other roads.

Why are urban interstates slower than rural interstates?

Urban interstates are often slower because state law sets separate maximums by land use, urban or rural, as well as by road type. IIHS says the posted limit on a particular section can also sit below that maximum when the agency in charge decides a lower limit is warranted.

The size of the drop varies a lot. Illinois and West Virginia fall 15 mph, from 70 mph to 55 mph. Missouri also falls 15 mph, from 75 mph to 60 mph. Other states show no drop at all in their general figures:

• Kansas lists 75 mph for both rural and urban interstates.
• Maine and New Mexico also list 75 mph for both.
• Georgia, Pennsylvania, Tennessee and Virginia list 70 mph for both.
• Massachusetts and New York list 65 mph for both.

A general figure of this kind tells you what a state allows. It does not tell you what is posted through a particular city, so keep reading the signs as the skyline gets closer.

Why do interstate speed limits change at state lines?

Interstate speed limits change at state lines because the federal government no longer sets a national maximum. Congress created a 55 mph national limit in the 1970s in response to oil shortages, and by March 1974 every state had adopted it. Congress let states raise rural interstates to 65 mph in 1987.

The National Highway System Designation Act of 1995 repealed the national limit. The Federal Highway Administration says the repeal took effect on December 8, 1995, in most states. Many states quickly raised their limits, and the patchwork you drive through today is the result.

What is the speed limit on I-95?

I-95 has no single speed limit, because each state along it sets its own. Rural interstate maximums along the route include 75 mph in Maine, 65 mph in New Jersey, 70 mph in Virginia and 70 mph in Florida. On a long East Coast drive, the first sign after each state line is the one to look for.

What is the speed limit on I-80?

I-80 changes in the same way. It runs from 65 mph in New Jersey up to 80 mph on specified parts of Utah and Wyoming, and Nevada lists 80 mph for rural interstates. On a coast-to-coast drive the number changes many times, and camera rules change with it, as our guide to which states have speed cameras shows.

Do trucks have a lower speed limit on interstates?

Yes, in some states, and seven states list a lower rural interstate limit for trucks than for cars. The gap ranges from 5 mph in Arkansas to 15 mph in California, and the lower number applies to the truck categories each state defines.

• Arkansas: 75 mph for cars, 70 mph for trucks.
• California: 70 mph for cars, 55 mph for trucks, and 55 mph for trucks on urban interstates too.
• Indiana: 70 mph for cars, 65 mph for trucks.
• Michigan: 70 mph for cars, or 75 mph on specified segments, and 65 mph for trucks.
• Montana: 80 mph for cars, 70 mph for trucks.
• Oregon: 65 mph for cars, or 70 mph on specified segments, and 55 mph for trucks, or 65 mph on specified segments.
• Washington: 70 mph for cars, or 75 mph on specified segments, and 60 mph for trucks.

Texas draws its own line on its 80 mph sections: IIHS says that limit is for passenger cars and light trucks. Eight Illinois counties, including Cook, DuPage and Lake, may also opt out of the state's 70 mph limit by ordinance, and they have their own limits for large trucks.

Is there a minimum speed limit on interstates?

Often yes: states can post a minimum speed, and driving too slowly can be an offense even where no minimum is posted. Virginia's code says nobody may drive so slowly that it impedes the normal and reasonable movement of traffic, unless a lower speed is needed for safety or to comply with the law. Virginia then lets highway authorities post a minimum limit where slow speeds consistently hold up traffic.

Texas has almost the same wording, and it also allows a posted minimum after an engineering and traffic investigation. In both states, slowing down for rain, fog or a work zone is covered by the safety exception. If the weather is bad, a lower speed is the right speed. Virginia is strict at the other end of the scale too, as our guide to its court-ordered speed limiters explains.

Do higher interstate speed limits affect safety?

Yes, research links higher limits to more deaths on the road. An IIHS study of 1993 to 2017 found that each 5 mph increase in a state's maximum limit was associated with an 8% increase in fatality rates on interstates and freeways. It estimated about 37,000 more traffic deaths over that period than if the 1993 limits had stayed in place.

The early results from North Dakota are worth a look too. The Highway Patrol counted 505 crashes in the new 80 mph areas from August 1, 2025, to July 31, 2026, up from 469 the year before. Crashes also rose in the sections lowered to 70 mph, from 53 to 65, and the patrol said it is difficult to draw conclusions from a single year of data.

IIHS also explains why a few extra miles per hour matter. Higher speed lengthens the distance you travel before you react, lengthens braking distance and raises crash energy disproportionately. When impact speed rises from 40 mph to 60 mph, the energy to be managed goes up by 125%. Any posted limit is a ceiling for good conditions, and rain, darkness or heavy traffic all call for less.

What do interstate speed limits mean for your next drive?

For your next road trip, the simple habit is this: use the table to plan, then trust the sign. Check the limit when you cross a state line, when you reach a city, and when you pass into a work zone. If you are towing or driving a truck, check whether your state has a separate number. A steady speed at or below the posted limit also makes for a calmer, less tiring day behind the wheel.

That is where Ghost fits in nicely. It runs quietly in the background next to any navigation app and warns you about known fixed speed cameras and average-speed zones, about 700 meters ahead (roughly 0.4 mile) and again at 250 meters, with one tone and no voice. It works on CarPlay, Android Auto and Apple Watch and covers more than 125,000 speed cameras worldwide, so a long stretch of interstate feels calmer and you can keep your attention on the road and on arriving safely.