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Speed Limits

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A 45 mph speed limit sign on a busy stretch of road​​​​​​​​​​​

​​​​​​​​​​​​​​​Automatic Speed Limits 

North Carolina law sets speed limits within town or city limits at 35 mph, unless otherwise posted. For areas outside of towns or cities, the speed limit is 55 mph, unless otherwise posted. Drivers, however, should slow down and be cautious based on driving conditions. ​
The N.C. Department of Transportation sets the speed limit for all state-maintained roads, including access-controlled highways, which are highways with medians that require drivers to enter or exit only at interchanges with bridges, inside the town or city limits.

For other state-maintained roads within the municipal limits, NCDOT and the town or city must concur before changing the speed limit.

​For any sign to be effective, it must command the respect of motorists. That means speed limits must be reasonable and enforced. NCDOT is responsible for establishing speed limits, but law enforcement officers have enforcement responsibility.

How Speed Limits Are Determined

​Roads are designed for a specific speed. NCDOT may review the speed limit for various reasons, such as part of a study to improve highway safety, or for proposed new developments.  Citizens and local officials may also request NCDOT to conduct a speed zone study to determine whether a road has the appropriate speed limits and signage. 

The department considers several factors when adjusting the speed limit, such as:

  • Alignment of the roadway
  • Types of development along the roadway
  • The density, or number, of driveways on a corridor
  • How far one can see on the road
  • Crash history
  • Various speed data

85th Percentile Speed​

One of the most common types of speed data NCDOT uses is based on the speed at or below which 85 percent of drivers are traveling. NCDOT uses the 85th percentile to help avoid posting speed limits that are artificially low, which can become difficult to enforce. In the absence of strict enforcement, most people drive at the speed they are comfortable with, regardless of the speed limit.

Statutory Speed Limits

For interstates and the primary highway system, North Carolina sets the following minimum speed limits, which are enforceable when signed along the road. Vehicles going slower than the speed limit in normal, dry conditions are unexpected and can pose a hazard. 

  • 40 mph minimum, if the speed limits is 55 mph
  • 45 mph minimum, if the speed limit is 60 mph or higher

In addition, some buses can’t exceed these speeds, under North Carolina law:

  • School buses: 45 mph
  • Activity buses: 55 mph

​Speeding Kills

Speeding is a major cause of injuries and deaths on North Carolina roads. Across the state, 424 people died in speeding-related crashes in 2021. For safe driving tips, see the “Speed a Little. Lose a Lot.​” campaign by the N.C. Governor’s Highway Safety Program.

Neighborhood Speeding Problems

Speeding on residential streets is a common complaint reported to NCDOT, even though in most cases, only a small percentage of the drivers are actually speeding.  People should report such problems to local law enforcement, which can increase patrols and run radar on trouble spots.

In most cases, neighborhood traffic is contributing to the speeding problem. Programs such as community watch or homeowner’s associations are ways to educate these drivers about the dangers of speeding. ​​​

Frequently Asked Questions

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  • What are special speed zones?

    ​Some areas such as school zones or construction work zones have special speed limits to improve the safety for pedestrians, highway workers and others. These slower speeds may seem inconvenient, but obeying them can prevent serious crashes or injuries. 

    Work zones may have speed limits that change due to the type of work that is being performed. For instance, the speed limit may be lowered with digital signs when there are lane closures. These changes can occur during the day or night.

    School zones are another area where the speed limit may change, based upon the time of day and if school is in session. It’s best to always assume a Monday through Friday is a school day.  ​

  • Does North Carolina have night-time speed limits that differ in the daytime?

    ​No, unlike some other states, North Carolina does not set differing speed limits for the same road that vary between the daytime and nighttime. 

    North Carolina employs variable speed limits using digital signs – the limits vary based on driving conditions, such as fog, regardless of the time of day.

  • How do I get a digital speed radar warning sign installed in my neighborhood?

    ​​NCDOT does not install or operate those portable devices. Typically, the local law enforcement agency will install them temporarily in areas experiencing speeding. The signs, which display a driver’s speed, are meant to educate people and help slow down drivers.

7/26/2022 9:16 AM