Basic Speed Law - Speeding - NHTSA

Know What the Basic Speed Rule Means

The Basic Speed Rule

Most drivers probably know that they must slow down in bad weather or when road conditions are hazardous. It is self-preservation. You don’t want to end up in an accident.

Still, speeding during unsafe conditions is a major cause of fatal accidents.

For your DMV knowledge exam, it is important to know that a traffic officer can stop and cite you for speeding, even if you drive at the posted speed limit.

This is known as the Basic Speed Law. You must always drive at a speed that is prudent and reasonable, regardless of what the speed limit sign says.

Situations When an Officer May Stop and Give You a Ticket

Situations when an officer may decide that your speed is unreasonable include:

  • Unsafe speed when going around a tight curve.
  • Driving too fast when approaching the crest of a hill.
  • Traveling too fast upon any narrow or winding roadway.
  • Going at the speed limit in fog or other low-visibility conditions.
  • Going too fast in heavy rain or snowfall.
  • Improper speed when road conditions are slick or icy.
  • Going faster than traffic around you.
  • Posing a potential hazard for children or pedestrians along the side of the road.

Read more: Meaning of the Basic Speed Law


What is the Basic Speed Law?

Reduce speed in bad weather


A basic speed law says that you must travel at a speed that is consistent with existing driving conditions. These include weather, traffic, and road conditions.

Or put in other words: No person shall drive a vehicle on a highway at a speed greater than is reasonable and prudent under the conditions.

Such a basic speed law is used in all 50 states.

Remember, it does not always matter what the speed limit sign says.

In bad weather, you must reduce speed. If there are potential hazards on the road, you must also drive slower than the posted speed limit.