Speed Regulations
Speed Limits Across the US

Speed Limits Across the US: Maximum Speed Limits, Violations & Penalties

Updated Oct. 20, 2020

Speed limits are set based on a variety of factors, including the type of road and the volume of traffic using that road at any given time. Sometimes, special speed limits are established for certain types of vehicles; for instance, trucks above a certain weight may be required to keep within a lower speed than other traffic using a roadway. You may also encounter stretches of road where the speed limit changes based on whether you are traveling during the day or at night.

Different states establish their own maximum and minimum speed limits based on these factors. The maximum speed limit on a rural expressway varies from 65 mph to 80 mph around America, with higher speed limits more commonly found in western states. Currently, the 85 mph is the highest speed limit in the country, which can be found in rural Texas on a limited stretch of tolled highway.

Unless otherwise stated, the example speed limits and associated traffic laws on this page are based on the California traffic code. They provide a general picture of speed limits, speed rules, fines and penalties around the United States, though you must keep in mind that speed regulations may differ in your area. Always refer to your state’s own driving manual for accurate information on speed limits in your state.

Basic speed law

Obedience of the basic speed law must take precedence over all posted and prima facie speed limits. This law states that motorists must never drive faster than is safe, based on current conditions. The basic speed law applies in California and many other states, though it may be named differently elsewhere.

Obeying this law requires good judgment. If the posted speed limit on a roadway is 65 mph but the presence of ice on the roadway means that driving close to this speed would be dangerous, drivers are legally obligated to reduce their speed to a safe level. You may be cited for breaking this law, just as you would be for driving faster than the posted speed limit.

You should abide by the basic speed law by reducing your speed below the posted speed limit, under any of the following conditions:

  • Traction on the roadway is poor, due to ice, water, mud, chemical residue or other factors
  • Visibility is reduced by rain, snow, fog, smoke or obstacles
  • An accident has occurred on the roadway
  • Emergency responders are conducting work on the roadway or shoulder
  • Your vehicle control is limited by mechanical problems, your own ill health or for any other reason

Maximum speed limits

Most speed limit signs refer to maximum speed limits. That is, the top speed at which a driver may travel while using a stretch of roadway, based on ideal driving conditions. Different types of roadway have different maximum speed limits.

In California, the highest speed you may drive at on any road is 70 mph. This only applies on certain highways where 70 mph speed limit signs are posted. On most Californian highways, the maximum speed limit is 65 mph. If the highway has two lanes and is undivided (opposing lanes of traffic are not separated by a central barrier), the maximum speed limit is 55 mph. Use your driving handbook to find out the maximum speed limits in your state.

Keep in mind that no two roadways are the same. Even if two highways appear identical to the untrained eye, the risk associated with driving on one may be significantly greater than the risk associated with driving on the other. State governments may post speed limits which are higher or lower than the norm for that type of road. Always look out for and obey posted speed limits.

Minimum speed limits

Minimum speed limits often apply on high-speed or limited-access roads, if traveling significantly slower than other traffic would be hazardous. In Florida, the minimum speed limit on interstate highways is 50 mph, where the maximum speed limit is 70 mph. In urban interstate zones with maximum speed limits of 55 to 65 mph, the minimum speed limit is 40 mph.

In most cases, minimum speed limits will be sign-posted, though this is not always true. Make sure you check for minimum speed limit rules in your state driving handbook, as you must know when they apply if speed limit signs are not posted.

The prima facie speed limit law

Prima facie speed limits set the maximum speed you may travel at on a certain type of roadway, which must be assumed if no speed limit signs are posted. Most states have established prima facie speed limits for:

All new drivers must find out what the prima facie speed limits are in their state, as they must be obeyed any time a speed limit sign is not posted.

Speed limits in business and residential districts

The prima facie speed limits in business districts and residential areas are generally among the lowest in the state. The high volume of road traffic, pedestrian traffic and other distractions that drivers usually encounter in these areas mean that additional caution and limited speeds are required, to maintain public safety.

In California, the speed limit is 25 mph in both business and residential areas. Many states also use the same maximum speed limit for both zones, while others differentiate between the two. Colorado, for instance, has a maximum speed limit of 25 mph in business districts and 30 mph in residential areas.

School zone speed limits

The lowest speed limits in each state usually pertain to school zones. Children are particularly vulnerable pedestrians, as they are easily distracted and may not understand the danger posed by traffic. Low school zone speed limits are imposed to protect children, parents and motorists alike.

Here are some examples of school zone speed limits:

  • California: 25 mph (posted speeds may be as low as 15 mph)
  • Florida: 20 mph (posted speed limits may be as low as 10 mph)

As shown by these examples, drivers must remember that posted signs may sometimes indicate a speed limit lower than the state’s maximum school zone speed limit. In some areas, lower limits may not be posted but may apply at certain times of day or under specific conditions. Read your driver’s handbook and make sure you know the rules!

Vehicle-specific speed limits

Many states impose speed limits on certain types of vehicles. In California, traffic law forbids any person driving any of the below-listed vehicles to travel above 55 mph on a highway. Several other states have similar vehicle-specific speed limits. Check your driving manual for details.

Motorists in California may not exceed 55 mph on any highway while driving:

  • Any vehicle transporting explosives
  • A passenger vehicle or bus towing any other vehicle
  • A school bus carrying school children
  • A trailer bus
  • A farm vehicle which is carrying passengers
  • Any motortruck or truck-tractor with three or more axles
  • Any motortruck or truck-tractor towing any other vehicle

Violations & penalties

Violate speed limit laws and you can expect to pay the price! If you are caught failing to adhere to a maximum (or minimum) speed limit, you will be fined and may be issued a penalty. Information on speed limit violations and their associated fines can be found in your driver’s handbook.

Keep in mind that some states treat excessive speed limit violations as criminal acts rather than civil offenses. This is usually the case when a motorist exceeds the maximum speed limit on a roadway by 20 mph or more. Such motorists would be required to attend criminal court and will be subject to harsher punishments, which may include a total driving ban or a jail sentence.

Speed limits on bridges and elevated structures

Special speed limits are sometimes set on roads passing over bridges and other elevated structures. This is usually because the risk or potential severity of an accident on the structure is greater, or because the structure itself may be damaged by vehicles traveling at speed. In both cases, speed limit signs will be posted at the start and end of the bridge to inform motorists.

Variable speed limits

On some roads, the speed limit is variable and will change based on current environmental and traffic conditions. As the speed limit is not constant, it is displayed on an electronic sign rather than a permanent printed sign. Variable speed limits improve safety, as motorists do not have to decide on an appropriate safe speed themselves when conditions are unfavorable. Electronic variable speed limit signs may include both a maximum and minimum speed limit.

Night driving speed limits

Several states impose nighttime speed limits on motorists using high-risk stretches of roadway. Such limits are usually 10 to 15 mph lower than day time maximum speed limits. Nighttime speed limits are usually posted immediately below daytime speed limits on the same sign-post, often with white or reflective numbers which can easily be seen in the dark. Your state’s driver manual should tell you whether nighttime speed limits apply in your area.

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