Questions and Answers

› Are radar detectors legal?

› What is "POP" radar?

› What's the best radar detector for me?

› How do radar detectors work?

› How do laser (LIDAR) detectors work?

› How does Safety Radar work?

› What are the radar bands?

Are radar detectors legal?

Yes, radar detectors are completely legal to use in non-commercial vehicles in 49 states. Only Virginia and Washington D.C. currently ban radar detector use in the United States.

Radar detectors are illegal to use in commercial vehicles over 10,000 lbs. and in most Canadian provinces.

What is "POP" radar?

"POP" mode is a relatively new feature for radar gun manufacturers. It works by transmitting an extremely short burst, within the allocated band, to identify speeding vehicles in traffic. Once the target is identified, or "POPPED", the gun is then turned to its normal operating mode to provide a vehicle tracking history (required by law).

What's the best radar detector for me?

This depends entirely on your needs. For the budget-minded driver that doesn't need all the bells and whistle, we recommend the Whistler XTR-690, Whistler PRO-78 or Beltronics Vector 955 radar detectors.

The next step up would be the Beltronics Vector 995 and Escort 8500 X50 Red (also available in Blue for $339.95) radar detectors. We personally recommend you spend the little extra for the Escort 8500 X50.

And finally, for those of you that need the best and you live life in the fast line: the Escort Passport 9500i Red (also available in blue for $499.95) radar detector.

How do radar detectors work?

Traffic radar, which consists of microwaves, travels in straight lines and is easily reflected by objects such as cars, trucks even guardrails and overpasses. Radar works by directing its microwave beam down the road. As your vehicle travels into range, the microwave beam bounces off your car, and radar antenna looks for the reflections. Using the Doppler Principle, the radar equipment then calculates your speed by comparing the frequency of the reflection of your car to the original frequency of the beam sent out.

Traffic radar has limitations, the most significant of those being that it typically can monitor only one target at a time. If there is more than one vehicle within range, it is up to the radar operator to decide which target is producing the strongest reflection. Since the strength of the reflection is affected by both the size of the vehicle and its proximity to the antenna, it is difficult for the radar operator to determine if the signal is from a sports car nearby or a semi-truck several hundred feet away.

Radar range also depends on the power of the radar equipment itself. The strength of the radar unit's beam diminishes with distance. The farther the radar has to travel, the less energy it has for speed detection.

Because intrusion alarms and motion sensors often operate on the same frequency as radar, radar detectors will occasionally receive non-police radar signals. Since these transmissions are usually contained inside of a building, or aimed toward the ground, they will generally produce much weaker readings than will a true radar encounter. As you become familiar with the sources of these pseudo alarms in your daily driving, they will serve as a confirmation that your radar detector's detection abilities are fully operational.

How do laser (LIDAR) detectors work?

Laser speed detection is actually LIDAR (Light Detection and Ranging). LIDAR guns project a beam of invisible infrared light. The signal is a series of very short infrared light energy pulses, which move, in a straight line, reflecting off your car and returning to the gun. LIDAR uses these light pulses to measure the distance to a vehicle. Speed is then calculated by measuring how quickly these pulses are reflected given the known speed of light.

LIDAR (or laser) is a newer technology and is not as widespread as conventional radar, therefore, you may not encounter laser on a daily basis. And unlike radar detection, laser detection is not prone to false alarms. Because LIDAR transmits a much narrower beam than does radar, it is much more accurate in its ability to distinguish between targets and is also more difficult to detect. AS A RESULT, EVEN THE BRIEFEST LASER ALERT SHOULD BE TAKEN SERIOUSLY.

There are limitations to LIDAR equipment. LIDAR is much more sensitive to weather conditions than RADAR, and a LIDAR gun's range will be decreased by anything affecting visibility such as rain, fog, or smoke. A LIDAR gun cannot operate through glass and it must be stationary in order to get an accurate reading. Because LIDAR must have a clear line of sight and is subject to some cosine error (an inaccuracy, which increases as the angle between the gun and the vehicle, increases) police typically use LIDAR equipment parallel to the road or from an overpass. LIDAR can be used day or night.

How does Safety Radar work?

Safety Warning System, or SWS, uses a modified K-band radar signal. The SWS safety radar system has 64 possible messages (60 currently allocated).

Since Safety radar technology is relatively new, and the number of transmitters in operation is not yet widespread, you will not receive Safety warnings on a daily basis. Do not be surprised if you encounter emergency vehicles, road hazards and railroad crossings that are unequipped with these transmitters. As Safety transmitters become more prevalent (the number of operating transmitters is growing every day), these Safety radar signals will become more common.

If Safety Warning System (SWS) is a feature you would like, be sure the radar detector you select has this feature included!

What are the radar bands?

Modern radar detectors include numerous "bands" of operation. Each band corresponds to a specific frequency range or function.

X BAND

The frequency range of the X band is 10.475 to 10.575 gigahertz. The X band was the first microwave radar band introduced. Almost all false alerts occur on the X band, because there are many stray signals in this frequency range. Some examples are automatic door openers at supermarkets, some security systems, and microwave transmission towers.

K BAND

The frequency range of the K band is 24.0 to 24.25 gigahertz. This is the second microwave radar band introduced by radar gun manufacturers. It is rare to get a false alert on K band, but automatic door openers are currently being manufactured that operate in the K band.

Ka BAND

The frequency range of the Ka band is 33.4 to 36.0 gigahertz. This is the newest microwave radar band. It is rare to get a false alert on Ka band.

LASER

Laser is light, so this is not a microwave radar band. The laser guns operate in the infrared region, which is invisible to your eye. The infrared region is extremely high in frequency, so it is typically described in terms of wavelength. It is extremely rare to get a false alert on laser.

VG2

A VG2 gun is a special device used by law enforcement to identify the presence of a radar detector. It looks like a radar gun, but it does not measure speed. It tells the officer if you are using a radar detector. It works because all radar detectors leak a small amount of signal. Radar detectors are currently illegal in Virginia, the District of Columbia, and most parts of Canada. Radar detectors are also illegal in all 50 states for commercial drivers (truck drivers, bus drivers, taxis and limos). If the above does not apply to you, then you don't have to worry about VG2.

SPECTRE and STALCAR

The Spectre and Stalcar work just like the VG2 gun -- they can identify the presence of a radar detector. Both are new models designed to replace the aging VG2 gun. Radar detectors that were invisible to the VG2 gun can be detected by the Spectre and Stalcar.

The above bands are all detection methods in use by law enforcement. The following bands are not for law enforcement, they provide safety information.

SAFETY ALERT

Designed by Cobra, Safety Alert is a system for alerting motorists to emergency vehicles or safety hazards. It requires a transmitter installed on the emergency vehicle. For radar detectors not equipped with Safety Alert, they will provide a K band warning. The motorist will then slow down and look around, taking notice of the emergency vehicle. For radar detectors that support this feature, it will provide a Safety Alert warning, notifying you that an emergency vehicle is nearby. Safety Alert transmitters may also be present at railroad crossings and construction zones. Not all emergency vehicles are using Safety Alert, each local municipality decides for themselves.

STROBE ALERT

Many cities have been using a special sensor mounted on traffic lights, which detects a special strobe light on emergency vehicles. When an emergency vehicle approaches the intersection, the light turns green for them. This system helps prevent accidents with emergency vehicles. Not all emergency vehicles are equipped with the special strobe light.