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Fairfax Speed Traps

Fairfax speed traps may cause a significant amount of hassle for drivers. A person who received a ticket in a speed trap may be required to pay significant fines and could be subject to having points placed on their record, which could cause problems for them later on. If you were caught in a speed trap and are facing consequences, consult a skilled Fairfax attorney to learn your options. A lawyer could review your case and build your defense.

Defining a Speed Trap in Fairfax

Nothing in the Virginia Code specifically defines the term “speed trap.” Colloquially, a speed trap is where the police wait on the side of the highway to catch speeders. The purpose of a speed trap is to ensure highly congested areas with frequent accidents are monitored for speed. Police officers at a speed trap check to see that drivers follow the speed limits to prevent accidents. While it may seem like a speed trap is for revenue, this is not the case.

There is usually a singular location with one or more officers on the highway or the interstate. Frequently, radar guns are involved. Speed traps are often seen during the holidays or at other times when there is heavy traffic, which could include ball games or other events. These traps may exist in congested areas on the interstate highways where traffic merges from one interstate to another with different speed limits.

One type of speed trap is when law enforcement officers are purposely waiting for speeders. A person might be pulled over when there is no speed trap and the officer observed the vehicle speeding and saw an accident or witnessed some other traffic violation.

If a speed trap is legally placed on the highway or is in a place that does not violate traffic laws or creates a traffic hazard, the law enforcement officers are legally allowed to check for speed. They must be located in Fairfax County and not in another jurisdiction.

Given that speed traps exist in Fairfax County, drivers should follow the speed limit even when no one is watching.

Do officers in Fairfax County Wait in Areas Where the Speed Limit Changes?

In certain cases, officers in Fairfax County wait in areas where the speed limit changes to look for drivers who do not adjust their speed accordingly. The most common locations are coming off the highways, down particular hills, and also at various turns where the speed changes from 55 miles per hour to 35 miles per hour. The police officer looks at whether a driver reduces their speed appropriately. If they do not, the officer may pull the driver over and issue a ticket.

Examples of Speed Trap Locations in Fairfax County

Many speed trap locations in Fairfax County are on the interstate highways such as I-95 and I-495. The primary places are roads with heavy traffic where there are changes in the interstate.

How Being Caught in a Trap Impacts a Person’s Case

Being caught in a speed trap does not have an effect on one’s case per se. When someone is caught in a location where an officer uses lidar or radar to track their speed, it does not mean their case is different. It does make for a per se case when the law enforcement officer has some form of electronic tracking device which follows the driver’s speed. It is most difficult to defend against such a case.

Methods Officers Use to Prove that They Recorded a Driver’s Speed

Law enforcement officers have lidar or radar guns approved by law enforcement agencies. While they are similar, they use different electronic devices and utilities to make an electronic calibration. The officer points a radar or lidar gun at the moving traffic and focuses on one vehicle to track and monitor its speed. Those are calibrated outside, usually in the station before an officer makes the traffic stop. The device is typically recalibrated after the traffic stop to ensure that it is within the degrees of accuracy.

Challenging an Officer’s Allegation of Speeding

In speed trap areas where a vehicle is being monitored and calculated using lidar or radar technology, it is difficult to prove that the vehicle was not going at the calculated speed. One possible defense is when several cars are in a lane at that time or two cars were next to each other. An argument could be made that the police officer’s radar or lidar gun detected another vehicle’s speed and not theirs.

Typically, it is difficult to prove that the calculated speed is not the speed the individual was driving. When the speed is 10 to 20 miles over the speed limit, the best one could hope for is claiming that the lidar or radar gun was not calibrated correctly even if the person was driving at a high rate of speed. While the speed might be reduced, they are still responsible for the ticket.

How Do Fairfax County LEOs Know that Individuals Were Speeding?

The code for the term used for a law enforcement officer is LEO. As an example, assault and battery on a law enforcement officer is normally referred to as an assault on an LEO or ALEO. It is commonly used for a Fairfax County police officer and how the court refers to them and is typically put on a police report. The term could appear as LEO Smith instead of Officer Smith.

There are several methods for tracking speed. Three commonly used speed detection techniques used by Fairfax County Leos are:

  • Lidar
  • Radar
  • Pacing

Lidar is a technology used to detect speed that works on the principle of radar while using light from a laser. When using a lidar, the State must prove that the lidar detector works. The officer must prove that the instrument was properly calibrated, tested, and was reading accurately on that specific day for the specific traffic stop. Radar uses a device that consists of a synchronized radio transmitter and receiver. It emits radio waves and processes their reflection to detect the speed of a vehicle.


Pacing is a technique a law enforcement officer is trained to do. The officer follows a suspected speeder and uses their own speedometer to clock the other vehicle’s speed. Traffic radar tools are often used to detect speed in Fairfax County. They are one of the most common ways speeding is detected.

The officer does not use a lidar or radar to capture the vehicle’s speed. They follow the vehicle and monitor their speed for at least several lengths of the vehicle to determine its speed. While it is not as accurate, an officer is usually able to accurately predict that a vehicle in a 55 mile per hour zone was traveling more than 55 miles per hour. They might get an estimate based on pacing of even 10 miles an hour over.

With regards to speeding instruments, individuals are typically under the impression that they are always accurate and there is no defense against them, or that the instruments are completely inaccurate. As a seasoned defense lawyer could explain, neither perspective is entirely true.

The Weight of a Radar Reading as Evidence in Court

A radar reading carries a strong weight in court and is similar to the use of a breathalyzer test in a DUI. Both machines are calibrated and put through testing and scientific analysis. They have been vetted by the court system as being accurate devices. The court system views them as being precise as long as the officer is able to prove that the instrument was calibrated beforehand, and there were no indicators of malfunctions. They used it in the way they were trained. When they are able to prove so, the court considers that extremely strong evidence and admits it. In certain cases, a radar reading is enough by itself to be beyond a reasonable doubt.

Traffic radar instruments used in Fairfax County are extremely accurate. They are put through testing before they are issued to law enforcement officers. They are usually calibrated daily, oftentimes several times a day. Since the instruments are put through rigorous testing repeatedly before and after being used, the accuracy could be determined and held to a reasonable degree of scientific certainty.

Potential Issues With Traffic Radar Instruments

Interference may be an issue when another object obstructs the use of the radar detector on a person’s car. Rain, wind, storms, snow, and other weather conditions might interfere with the radar signal to the point of giving false readings. Buildings, billboards, large trucks, and other large objects could distort the radar reading. When traffic is heavy, it is possible that the radar picked up the speed of a nearby vehicle.

While operator error is also possible, it is not common. Law enforcement officers must be trained and have experience using the radar gun and the lidar gun. Occasionally, there are officers who have not had the proper training or do not enough experience using them. They could be questioned about how they used the gun. Using the gun is part of the equation even more than the accuracy of the gun itself.

Lidar is the same as radar regarding defenses to this type of technology. The technologies are somewhat similar in that they are based on a digital read.

Definition of Pacing in Fairfax County Speeding Cases

Pacing is another method of determining the speed of a vehicle. A law enforcement officer drives behind the target vehicle and accelerates to match the speed of the vehicle ahead so that the distance between the two vehicles is static. The officer follows the target vehicle for a distance of a specific number of car lengths while keeping track of the speed on their own speedometer.

When a police officer is traveling in compliance with the speed limit and someone passes their car, they know without using a radar gun or lidar detector that the individual is speeding. They track the vehicle for at least several car lengths and sometimes the several miles depending on the situation. They keep pace with the vehicle to determine the speed.

Is Pacing Admissible Evidence in Court?

Pacing is admissible evidence of speeding. It is not as concrete as lidar or radar but it is completely admissible and is highly favored by the court because the officer is usually trained to do pacing. The officer has to establish that they know what pacing is, they are trained in pacing, and they have experience in pacing. They may testify that, based on their training and experience, they paced a person’s car and found the driver was traveling over the speed limit.

Defenses that Could be Used Against Pacing Evidence

Radar, lidar, and pacing speeding cases are difficult to defend. The best type of defense in a pacing case is that the officer does not know the specifics. Even if the officer is able to say the driver was driving more than 55 miles per hour, an argument could be made about the exact speed. The defense lawyer might argue for a limit to the rate of speed the accused might be convicted for. Unless there is something outside of the driver’s control such as an emergency, there is not much of a defense to be found not guilty of speeding, most of it is mitigation. Going with the flow of traffic is never a speeding defense. That argument does not hold up in court. The court knows that drivers are confined to the actual posted limit even when other drivers are going much faster.

Consult an Attorney Experienced With Fairfax Speed Traps

Fighting speeding cases involving Fairfax speed traps could become an overwhelming challenge. There are various methods police officers could have used to determine a person’s alleged speed, each of which requires a certain level of technical knowledge understanding.

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