Police radar is used by law enforcement to detect the speed of passing vehicles. Understanding how radar works and its limitations can help drivers avoid speeding tickets.
How Police Radar Works
There are three main types of police radar used in the United States:
- Radio Detection and Ranging (RADAR)
- Light Detection and Ranging (LIDAR)
- VASCAR
RADAR uses radio waves to determine a vehicle’s speed. The radar gun transmits radio waves at a set frequency which bounce off moving objects and return to the gun. By calculating the change in frequency between the transmitted and reflected waves, the radar gun can determine a vehicle’s speed.
LIDAR uses infrared light pulses instead of radio waves. The beam is much narrower than radar, allowing officers to target specific vehicles. The device measures the time it takes for each pulse to reflect back to calculate the vehicle’s speed.
VASCAR or Visual Average Speed Computer and Recorder uses two sensors placed a known distance apart. The officer manually times how long it takes a vehicle to travel between the sensors and then calculates the speed.
Limitations of Police Radar
While radar is an effective speed detection tool, it does have some limitations:
- RADAR guns have a narrow directional beam and can only measure the speed of one vehicle at a time.
- RADAR needs a clear line-of-sight and does not work well in bad weather.
- Newer radars can only detect speeds in the direction the officer is facing.
- Officers must be able to properly calibrate and operate the radar gun.
- RADAR guns are less reliable at very low speeds.
How to Avoid Radar Detection
While no driving behavior can guarantee avoiding radar detection, the following tips can help reduce your chances of getting a ticket:
- Obey the speed limit – This eliminates the need to evade radar in the first place.
- Watch for police vehicles and radars ahead – Slow down if you see a police car parked or patrolling.
- Maintain a steady speed – Radars detect changes in speed better than constant speeds.
- Keep your distance from other vehicles – Police target bunches of speeding cars.
- Avoid weaving in and out of traffic – Changing lanes draws more attention.
Alternative Speed Monitoring Technologies
Beyond radar, police have other speed detection options including:
- Pacing – The officer matches your speed to clock you.
- Aircraft enforcement – Police monitor speed from the air.
- Traffic cameras – Fixed cameras track speed in problem areas.
- Passenger detection – Officers visually estimate based on experience.
So even if you avoid radar detection, police have other methods to catch speeders.
Conclusion
Police radar allows officers to accurately measure vehicle speeds, providing strong evidence to issue speeding tickets. While limitations in radar technology exist, actively jamming police radar is illegal in many jurisdictions. The best way to avoid the hassle and expense of speeding tickets is to obey posted speed limits and drive safely.