Speed Reading Instruments

At an administrative hearing for a speeding ticket, officers show the hearing examiner that they are trained and certified in the method used to calculate the driver’s speed. Depending on the method used, the officer proves that the equipment was fully operational at the time the driver’s speed was recorded.

It is always the driver’s word against the officer’s, but the accused may be able to use a defense against the alleged speed they were traveling. Typically, the three common methods officers in DC use to determine an individual’s speed are pacing, radar, and LIDAR. Therefore, if the device used was not properly calibrated or was operated improperly the individual, or their DC traffic lawyer, may use that as a defense.

Radar Guns

A radar gun uses radio signals that bounce off a moving object and return to the radar gun. The radar gun then analyzes the signals to determine the speed of the moving vehicle and displays the speed on a screen for the officer to read.

Radar readings carry a lot of weight at hearings because it is difficult to convince the hearing examiner that a sophisticated piece of equipment is incorrectly analyzing the speed information.

Nevertheless, there are a few defenses to radar gun readings at an administrative hearing including:

Improper or Lack of Recent Calibration

For proper calibration, a radar gun must be checked for its accuracy against an object that is traveling at a known speed. An officer can determine if the radar gun is properly calibrated if the speed on the gun matches the known speed of the object.

When the radar gun is calibrated correctly, the gun is extremely accurate and difficult to defend against in the hearing.

Calculating a Different Vehicle’s Speed

The calculation of another vehicle’s speed is likely to occur if another vehicle is larger than the vehicle of the individual who received a citation, such as a truck that is rapidly coming up behind the ticketed vehicle in the same lane. An officer may see the ticketed vehicle, but the radar gun is calculating the truck’s speed.

Interference of Radio Signals

Additionally, interference may occur due to adverse weather conditions. On windy days, tree leaves or dirt can be read by the radar gun instead of the person’s vehicle speed. Moreover, rain that is blowing from extreme winds can reflect enough energy to give the radar gun false signals, especially if the rain is blowing in a horizontal direction.

Operator Error

Operator error may be common when officers do not realize that at a distance of a few hundred feet, a radar beam is wide enough to cover four lanes of traffic. It is possible that the officer reads a nearby vehicle instead of the ticketed vehicle because of the wide range of the radar beam. It is important to always determine if the officer who issued you the citation was given any formal training specifically for operating radar guns.


LIDAR uses a low power beam of laser light that bounces off a targeted vehicle and returns to a receiver in the unit. The unit calculates the speed of the targeted vehicle, which is read by the officer.

Such devices are considered to be more accurate than radar guns. However, to be accurate, the officer must hold the beam on the same part of the targeted car during the entire reading of the vehicle’s speed. This can be tricky for some officers because the beam is very narrow. It is often impossible to be sure that the beam is on the same part of the targeted car because an officer is not able to see the beam as it is being pointed.


Pacing occurs when an officer maintains a constant distance between their police vehicle and the targeted individual’s vehicle long enough to make a reasonable, accurate estimate of the speed based on the officer’s speedometer.

Pacing is admissible as evidence of speeding, however, an officer must prove the speed they were driving and that their speedometer was properly calibrated. They must also prove the distance the targeted vehicle was followed and the distance between the targeted vehicle and the police vehicle.

Some issues or defenses regarding pacing and speeding cases include hills, curbs, stop signs, and traffic lights. The presence of these can help an individual prove that an officer did not pace them for a long enough period, especially if these conditions stop their vehicle from traveling continuously.

Additionally, the more distance between the officer and the targeted individual, the less accurate the pace. An officer must keep an equal distance between the police vehicle and the targeted individual’s vehicle for the entire time the pacing occurs. Furthermore, pacing is more difficult when it is dark outside. Pacing is most accurate on straightaway roads where an officer can see and follow a vehicle for a continuous amount of time.

Police Radar Detectors

To avoid being pulled over by the police for speeding, some individuals purchase electronic devices to alert them to radar equipment in the area. Radar detectors use a receiver to detect emissions from a police radar gun and raise an alarm to the driver using it when a transmission is detected. There is a possibility that the detector could give off a false alarm because automatic door openers also operate in the same spectrum as radar guns.

In DC, however, it is illegal to possess a police radar detector. As such, a person should not have it in the vehicle with them if they are planning on traveling through DC. Even if the detector is turned off and disconnected, it is illegal to possess the detector, and by having one, a person is at risk of having the detector confiscated and receiving a citation.

Police officers have access to technology that allows them to determine if an individual has a police radar detector. Essentially, a person is at a great risk of paying a fine and having the device seized if they are traveling in or through DC with a radar detector. The best way to avoid such penalties is to not have the device in their possession while traveling the DC area. Additionally, although the detector intercepts transmissions from radar guns, radar guns are not the only method that police officers will use to determine if a person is speeding. Furthermore, those individuals who use radar detectors are at greater risk of having an accident than individuals who do not use them.