Are Speed Traps Legal? (June 2025)

What Is a Speed Trap?

Speed traps can take many forms, including both non-automated and automated.

Non-Automated Speed Traps

The phrase “speed trap” has existed for a long time. It could refer to any location where a police officer waits near a road to measure drivers’ speeds and stop speeders. Thus, the state trooper sitting in the trees with a radar gun could broadly be described as operating a speed trap.

But there are also a few more nuanced definitions for speed traps. In the days before radar guns, officers would use distance markers to estimate a driver’s speed based on the time required to span them. This process was notoriously inaccurate since fractions of a second could throw off the calculation.

Speed traps also refer to a law enforcement tactic that unfairly “traps” speeders, such as:

• Enforcing speeding laws at the base of a hill
• Setting up enforcement zones where speed limits drop without warning
• Hiding speed limit signs near trees or billboards

Often, small cities use these types of speed traps to supplement their revenue. Anecdotal evidence suggests that some towns with only a few hundred residents issue millions of dollars of tickets to people passing through using these strategies.

Generally, these types of speed traps are legal. However, California law prohibits old-fashioned speed traps where the speed limit suddenly drops without justification or the police use the inaccurate process of measuring speed by timing the distance traveled.

Since radar guns are nearly universally issued by police forces, measuring speed manually is almost obsolete. Speed traps involving drops in the speed limit are still occasionally used in small towns straddling highways, though. California law allows enforcement in these areas if a state survey has shown that the lower speed limit is justified. It only prohibits cities from lowering speed limits without proving the need for it.

Automated Speed Enforcement

Current usage refers to “speed traps” as locations with automated speed enforcement systems. These systems use built-in radar guns and cameras to perform the following:

• Measure the vehicle’s speed
• Capture a photograph of the vehicle’s license plate
• Store or transmit the information to a server to issue a ticket to speeders

These systems usually operate without supervision. In other words, most states that use automated speed enforcement do not require a human to review the system’s citations before mailing them to alleged speeders.

States usually set a margin to allow for speedometer inaccuracies. For example, many automated systems only deem a driver to be “speeding” when their speed is five or ten miles per hour over the limit.

Studies prove that automatic speed enforcement reduces speeding if drivers know where the systems are set up. In other words, fixed systems allow drivers to moderate their driving behaviors to avoid receiving an automatic ticket. This makes these systems especially useful in locations where a state has a special interest in preventing speeding accidents, such as work zones and school zones.

Moreover, some states limit where or how automated speed systems operate. For instance, Iowa allows speed cameras but limits their use as follows:

• Cities must obtain a permit to operate an automated speed enforcement system
• Only cities with over 20,000 residents can apply for a state permit
• The system only issues citations to drivers speeding by over 10 miles per hour

These types of limits try to balance the needs of police agencies to use the tools necessary to reduce speed-related auto accidents with the fair use of those tools.

Where Is Speed Trapping Illegal?

So are speed traps legal in every state in some form? Each state determines the tactics its law enforcement agencies can use to catch speeders. Most states allow tactics considered “speed trapping,” even if the circumstances seem unfair to drivers.

This means the police can usually set up enforcement areas at the base of a hill. Speed traps on highways and other high-traffic areas may be allowed as well.

However, nine states prohibit the use of speed cameras. The following states have laws banning the use of speed cameras:

• Texas
• Virginia
• Wisconsin
• New Jersey
• Maine
• New Hampshire
• Mississippi
• South Carolina
• West Virginia

One state, Nevada, allows automated speed cameras but only when human law enforcement officers are present. Two states, Utah and Arkansas, only allow them in certain areas, like school zones, residential neighborhoods and railroad crossings.

Contact ConsumerShield to Learn More About Speed Traps

Speeding tickets, including automated citations, can affect your insurance rates or even result in a license suspension. How long does a speeding ticket stay on your record? It depends on the state. Thus, the best way to avoid the effects of an unfair ticket is to beat it in court.

The knowledgeable team at ConsumerShield helps people understand their legal rights and find a trusted local lawyer to defend them. Contact us for a free case review and an attorney referral today.