All of us have seen a cop on the side of the road holding a radar / laser gun to detect speed, but there are different types of radar and laser that you should be aware of and we will go over some of the technology behind them. Do radar / laser detectors really work? We want to educate you on the different types of radar and laser detectors and what you can do (if anything) to protect your wallet from a hefty speeding ticket.
Laser or Lidar
The newest way for the cops to clock you as you cruise down the freeway is using a laser or LIDAR gun to detect your speed.
The primary difference between LIDAR and radar, is LIDAR uses much shorter wavelengths of the electromagnetic spectrum, typically in the ultraviolet, visible, or near infrared range.
Police laser uses laser light pulses rather than radar radio waves for speed detection. The laser speed gun has found its way into the hands of state and local police in at least half the country.
The advantages of a laser gun are compelling: the laser light beam is far narrower than a radar beam, allowing more accurate pinpointing of a specific vehicle; and the time needed for capturing a speed reading is less than half a second versus 2 to 3 seconds for radar.
The drawbacks are also important to note: laser guns are very expensive, they can’t be used from a moving vehicle or from behind glass, and accurate aiming requires a tripod or a very steady hand. 
Jamming Laser or LIDAR?
There are no Federal laws against the transmission of infrared light. Therefore, laser jammers are legal in most states except while on a military base and/or in a commercial vehicle weighing over 10,000 pounds. States that have banned the use of all jammers include California, Colorado, Illinois, Minnesota, Nebraska, Oklahoma, Utah, Virginia, and Washington DC.
The Problem with Detectors
For starters, they are expensive. The V1, retails at about $399. Secondly, by the time the detector beeps to warn you of a speed trap, it’s too late. The laser gun is “instant on”, meaning the gun isn’t detectable at all times, only when it’s directed at your car. The second the beam hits your car, the laser instantly reads your speed, and that’s what causes the detector to beep.
Why Trapster Works
Trapster does not depend on detecting laser. Trapster is crowdsourced, meaning Trapster’s 2.5 million users enter locations of speed traps, in turn sharing the location with all other users. This is a win win situation because the motorists will slow down when alerted of a trap, and that is exactly what the police want.
“It’s not hurting our job for public safety. When they put that stuff out there, they slow down at that spot we are at. It is actually helping with public safety.”
- Gabriel Medrano, Texas Dept. of Public Safety
Radar
Police have been using radar guns to detect the speed of vehicles since the 1950’s. There are a few different bands of radar used to determine speed, which makes it difficult for drivers to be able to detect them all, or detect the newest band for the cops to use. For information on all the radar bands police are using, see the next section “Different Bands of Radar”.
How to Detect cops Using Radar Guns
A radar detector is a passive electronic device used by motorists to determine if their speed is being monitored by law enforcement agencies via a radar unit, thereby potentially avoiding prosecution for speeding. Only doppler radar-based devices can be detected. Most of today’s radar detectors detect signals across a variety of wavelength bands — usually X, K and Ka (as well as Ku, in Europe.)
Radar Jammers
Radar jammers work on the principle of interfering with or overwhelming the doppler shift that occurs from the reflected radar beam that police RADAR guns require to obtain a vehicles speed.
Unlike police laser (at least in most states), police RADAR can not be legally jammed, in fact, any attempt to do so (whether one is successful or not, most active radar jammers are not) is a federal offense and violates FCC regulations. Simply put: you can be sent to jail if caught using a radar jammer.
Why Trapster Works
Trapster does not depend on detecting radar. Trapster is crowdsourced, meaning Trapster’s 2.5 million users enter locations of speed traps, in turn sharing the location with all other users. This is a win win situation because the motorists will slow down when alerted of a trap, and that is exactly what the police want.
“Having (motorists) slow down on their own is a lot less manpower-intensive than having us forced to spend time writing tickets. Whether they slow down because their friend told them to slow down (by using Trapster) or a ticket, the net effect is the same: They’ve slowed down.”
- Sgt. Brent Barbee, Amarillo Police
Different Bands of Radar
For those who want to dig deeper, here’s some technical jargin and history about different bands of radar.
X-Band
The X-band frequency is allocated for police radar: 10.5 – 10.55 GHz. It dates back to the 1950s and is the easiest band to detect because of its lower frequency and higher power output. Depending on terrain, temperature, and humidity, X-band radar can be detected from a distance of 2 to 4 miles, yet it only takes accurate readings of speed from a distance of 1/2 mile or less.
K-Band
K-band is the most frequently used radar frequency band: 24.05 – 24.25 GHz. K-band made its appearance in 1978. The first K-band hand-held radar guns could only be used from a stationary position. Later, a “pulsed” version was introduced that could be used from a stationary or moving vehicle.
K-band radar waves have a relatively small wavelength. At the power level found in police radar guns, K-band has an effective clocking range of about 1/4 mile. Depending upon terrain (around a corner, over a hill, etc.), K-band waves can be detected from a range of 1/4 mile to 2 miles.
Ka-Band
In 1987 the FCC allocated a frequency on yet another band, Ka, for police radar use. Ka-Band incorporates Ka-band, Ka Wide-Band, and Ka Super Wide-Band. With Ka came the introduction of photo radar (also known as “photo-cop”). The photo-cop system works at 34.3 GHz and combines a Ka-band radar gun with an automated camera (see Photo Radar below).
The FCC later expanded Ka-band radar use to a range of 34.2 to 35.2 GHz. This became known as Ka Wide-Band.
The introduction of the “stalker” radar gun raised the stakes in the detection game. Unlike all previous guns, the Stalker can be FCC licensed for any frequency in the Ka-band between 33.4 GHz to 36.0 GHz, and so cannot be picked up by detectors designed only for X, K, and photo radar. Today, Stalker guns are being used in more than half the country.
In response, manufacturers have developed detectors with “Super wide-band” technology that sweeps all of the Ka-band allocated to radar, as well as providing continued protection against X, K, and photo radar.
Ku-Band
Ku-band radar ranges between 12 and 18 GHz. It is used primarily in Europe for satellite communications, in both aerospace and broadcasting. In the radar enforcement realm, Ku is set at 13.45 GHz by the FCC and has only recently been introduced to the U.S. for speed detection.
How to Stay One Step Ahead
We hope we have helped educate you on the different methods police use to detect your speed when setting up a “speed trap”. If you plan on buying a radar detector, laser detector, and/or laser jammer expect to spend between three and five hundred dollars. But remember they are not legal in all states. There are other tactics like using a CB radio to communicate with other drivers on the road to get a heads up on speed trap locations. Some people use all of these devices to protect themselves while traveling. See one of our Trapster users in action using multiple devices to avoid a speeding ticket, Trapster Videos from Our Users.
More info and sources: radardetector.net Wikipedia, Crutchfield Learning Center
Creative Commons photos from Flickr: DSCN0362 by aslinth, live police photo from gdoolittle
