Police radar stands as a cornerstone of speed enforcement globally. Understanding its nuances is crucial for drivers aiming to navigate roadways responsibly and avoid unwarranted speeding tickets. This guide delves into the workings of police radar, particularly its capability to monitor multiple vehicles, and provides insights into how to remain vigilant and compliant.
Updated: 04-01-2024 by Veil Guy
Understanding Police Radar Technology
Police radar, short for RAdio Detection And Ranging, is a technology employed by law enforcement to measure the speed of vehicles. Unlike police laser, which targets individual vehicles with a focused beam, radar emits radio waves to detect speed. It operates on the Doppler effect principle, analyzing the frequency shift of radio waves reflected off moving vehicles to determine their speed. Think of the changing pitch of a siren as it approaches and recedes – radar uses a similar principle with radio waves.
Modes of Operation for Police Radar Systems
Police radar systems are deployed in two primary operational modes:
Instant-On Police Radar Operated from Hidden Position
Constant-On Radar: Continuous Monitoring
Constant-On (CO) radar involves the continuous transmission of radar waves. In this mode, the radar device constantly emits signals and automatically displays the speeds of vehicles within its detection range. Law enforcement officers can configure the radar to focus on a specific distance range, typically under 1000 feet, and set a speed threshold. This allows them to filter out vehicles traveling below a certain speed, concentrating on potential speeders. For instance, in a 65 mph zone, an officer might set the radar to only register speeds above 75 mph, offering drivers a slight margin.
Generally, Constant-On radar is detectable at a considerable distance by quality radar detectors, providing drivers with ample warning. However, some speed traps utilize Constant-On radar in ways that can challenge detection. Officers may operate from concealed positions, such as within median foliage, aiming their radar guns at an angle across the road rather than directly at approaching vehicles. These tactics can significantly reduce detection ranges even for advanced radar detectors. Similarly, targeting vehicles from behind, like from a highway on-ramp after an overpass, poses detection challenges, especially when using low-power K-band patch antennas like those in the Kustom Signals Raptor RP-1 radar gun.
Police Radar: Constant-On Radar in Stationary Position:
Constant-on police radar video demonstration
Instant-On Radar: On-Demand Speed Checks
Instant-On radar, technically known as RF-hold, operates in a standby mode, transmitting radar waves only when needed. When an officer spots a vehicle suspected of speeding, they can activate the radar instantly to get a speed reading and then quickly turn it off. Introduced in the early 1980s as radar detector usage became more prevalent, Instant-On radar was designed to counter radar detectors. A detector cannot alert to a signal that isn’t being transmitted.
This method is particularly effective when used at night, from overpasses or on-ramps, or from hidden spots in medians or shoulders. Handheld radar guns like the Kustom Signals Falcon HR are often used in Instant-On mode, making detection even more difficult. Officers using Instant-On radar are typically more actively observing traffic speeds, using radar to confirm visual estimations of speeding, ideally at distances under 1000 feet. However, in practice, Instant-On radar is sometimes used indiscriminately, targeting vehicles even at long distances where visual speed assessment is unreliable.
While speeding tickets issued based on questionable Instant-On radar practices might be contestable in court, success depends on having solid evidence, like video footage, and knowledge of local radar operation guidelines.
Quick-Trigger Radar: Rapid Speed Measurement
Quick Trigger (QT) radar is essentially a very rapid form of Instant-On operation, with extremely short bursts of radar transmission. Detecting QT radar demands both sensitivity and quick reaction from a radar detector. A detector that is sensitive but slow to process signals might miss these brief radar bursts. Therefore, a radar detector adept at handling Instant-On and Quick-Trigger radar is vital.
Police Radar: Instant-On (I/O) and Quick Trigger (QT) Radar Detection:
Video demonstration of instant-on radar
Speed Acquisition Time of Police Radar
Modern digital police radar guns can determine vehicle speed incredibly quickly, in as little as 100 milliseconds. This rapid speed acquisition time leaves minimal reaction time for drivers, especially when Instant-On or Quick-Trigger radar is used. For effective protection, a radar detector must not only be sensitive enough to detect weak radar signals from a distance but also fast enough to react to these brief radar transmissions. Recent radar detector reactivity tests have highlighted the varying capabilities of top radar detectors in detecting both K-band and Ka-band radar quickly.
Types of Police Radar Frequencies
Police radar guns operate on three main frequency bands: X band, K band, and Ka band. Newer radar guns primarily use the super-wide Ka-band, while K-band remains common due to its historical prevalence. The older X-band radars are gradually being replaced by newer, smaller digital Ka-band models and police laser technology, especially in areas like New Jersey.
Radar transmissions are broad and tend to scatter, offering radar detectors multiple opportunities for detection. This typically gives drivers enough time to react and slow down when vehicles ahead are targeted. However, some European radar systems like Gatso and Multanova use narrower, low-power, and polarized beams, making them harder to detect even with high-end radar detectors. These systems often include cameras and can be either fixed or mobile.
Redflex, a photo enforcement company, uses a particularly challenging type of radar that is horizontally polarized and low power, providing minimal warning time for most detectors. Redflex systems are contracted by municipalities for speed enforcement. Another difficult-to-detect radar is the frequency-modulated type used in Gatso RT4 red-light and speed-on-green photo enforcement systems. Fortunately, Redflex and Gatso RT4 systems are stationary, allowing GPS-based apps like Waze to warn drivers of their locations.
Portable handheld police radar is used from patrol vehicles or, less commonly, by officers outside their vehicles or on motorcycles.
Manufacturers of Police Radar Guns in North America
The primary manufacturers of police radar guns in North America include:
Police Radar Frequencies in North America
The main police radar frequency bands used in North America are:
Common Police Radar Frequencies:
- X-band: Centered at 10.5 GHz
- K-band: Centered at 24.1 GHz
- Ka-band: Centered at 33.8 GHz, 34.7 GHz, 35.5 GHz
Contrary to some advice, disabling K-band detection on radar detectors is not recommended. K-band radar is still actively used across many states and Canadian provinces. While it might reduce false alerts in some areas, it significantly increases the risk of missing real police radar threats.
Prevalence of Police Radar Frequencies
The most frequently encountered police radar frequency on highways is 34.7 GHz, often used by state police with Kustom Signals radar guns. The second most common Ka frequency is 35.5 GHz, used by Stalker radar, prevalent in many states. MPH 33.8 GHz Ka radar is less common but can be found in states like Nevada, West Virginia, and Ohio. K-band at 24.1 GHz is also widely used, particularly by county police, sheriffs, and in smaller towns. X-band radar at 10.5 GHz, primarily from MPH, is the oldest and still in use in pockets like Ohio, New Jersey, and Mississippi. For detailed information on state-specific radar use, resources like RadarBusters offer police radar by state charts.
Police Radar Use from Patrol Cars
Police radar can be operated when a patrol car is stationary or moving (patrolling).
Stationary Radar Operation
In stationary mode, officers park along highway medians, shoulders, on-ramps, or in parking lots, especially in areas with reduced speed limits. They may also position themselves off-highway, concealed behind trees, as is common on highways like the Atlantic City Expressway in New Jersey.
Patrolling (Moving) Radar Operation
Most states allow radar operation while the patrol vehicle is moving (except Pennsylvania). This enables officers to patrol and cover wider areas. Moving radar can be particularly challenging to detect, especially in Instant-On mode, due to the combined speed of approach, creating ambush situations. Unmarked patrol vehicles further complicate early detection. Whether patrolling, radar can be used in Constant-On or Instant-On modes:
Instant-On Police Radar: Patrolling (Moving I/O Radar):
Video demonstration of moving instant-on radar
Constant-On Police Radar: Patrolling (Moving C/O Radar):
Video demonstration of moving constant-on radar
Radar Capability to Measure Speeds in Both Directions
Pennsylvania uniquely restricts radar use to state police only. In most states, both state and local police can use radar for traffic enforcement. Some police vehicle-mounted radar systems have dual transmitters, one facing forward to monitor oncoming traffic and one rear-facing to clock vehicles approaching from behind. The rear transmitter can easily detect vehicles following a patrol car, so drivers should be aware when approaching patrol vehicles on highways. Radar, even in Instant-On mode, is generally detectable from ahead with a good detector, making it a valuable tool for drivers. Even budget-friendly detectors like the Whistler CR97 can be effective, while higher-end options are available from Escort, Radenso, Uniden, and Valentine Research.
Radar’s Ability to Track Multiple Vehicles Simultaneously
Modern dash-mounted police radars, often referred to as police speed scanners, can measure the speed of multiple vehicles at once, typically up to two. However, advanced systems can now target several vehicles simultaneously, identifying the fastest and the one with the strongest radar reflection. In such cases, the officer must visually confirm which vehicle is the actual speeder among the group. This capability to scan multiple cars is crucial in heavy traffic scenarios.
Understanding POP Radar Technology
POP radar was introduced to challenge radar detector effectiveness by using very short radar bursts. The initial concept was to transmit a radar pulse for only 67 milliseconds, too brief for conventional detectors to reliably detect while they cycle through different frequency bands (X, K, and Ka). While the 67ms POP has been largely countered by modern radar detectors, MPH, the technology’s developer, introduced an even faster 16ms version.
POP radar typically operates on the 33.8 GHz Ka-band but can also be found on MPH’s K-band handheld guns. Nevada is a known area for POP radar use, where police are highly trained with these units. Even top detectors like the Valentine One can struggle with the 16ms POP, detecting it sporadically. Despite its initial promise, POP radar never became widely adopted, and its advantages have been overshadowed by the rise of police laser (LIDAR), which is easier to use and more effective for speed enforcement. Unless POP radar is known to be in use in a specific area, enabling POP detection on a radar detector might reduce overall detection performance due to increased false alerts.
States Known to Use POP Radar
While some states have contracted with MPH and may use POP radar guns, including Florida, Georgia, Iowa, Mississippi, Nevada, New York, and Oregon, its widespread use is not confirmed. Police laser has become the preferred method of speed enforcement. In practice, POP radar encounters are rare. Radar detectors need to be specifically enabled to detect POP, and not all models offer this capability. Moreover, POP detection can increase false alarms and reduce detection range for conventional radar. Unless there is specific intelligence indicating POP radar use in an area, it’s generally advisable to keep POP detection turned off. Officially, tickets should not be issued solely based on POP readings, but enforcement practices can vary.
Accuracy of Police Radar
Police radar is generally very accurate. While performance can be affected by severe weather, accuracy remains high, though effective range might decrease. Newer digital signal processing (DSP) radar guns are more precise and can measure speeds from greater distances with less transmission power, making them harder to detect.
Radar Range for Speed Detection
Speed measurements are typically taken within 1000 feet, sometimes closer in concealed stationary setups. Modern radar detectors generally offer detection ranges far exceeding this. However, instances of radar speed detection at 2500-3000 feet are reported, especially with advanced systems like the Stalker Dual 34.7 Ka radar. The latest digital police radars can achieve speed readings at distances up to 3500 feet or more.
Police Radar Range Tests with Kustom Signals Raptor RP-1:
Speed detection range of a Kustom Signals Raptor RP-1
Is Police Radar Infallible?
No, police radar is not foolproof. Speed readings can be missed due to operator errors like premature trigger activation in Instant-On mode, or environmental factors like heavy rain, which can absorb radar signals and reduce range. Obstructions, such as another vehicle passing between the target vehicle and the radar beam, can also temporarily prevent speed readings.
Value of Radar Detectors
Radar detectors are highly valuable for drivers seeking to avoid speeding tickets. Effective radar detectors alert to police radar, laser, and photo enforcement systems. The cost of a detector can quickly be offset by avoiding just one or two speeding tickets, along with the associated points and insurance premium increases. Rankings of the best radar detectors are available for reference.
Outbraking Police Radar
Outbraking police radar is possible under certain conditions:
- If a radar detector provides early warning of an Instant-On trap.
- With Constant-On radar, which is usually detected with sufficient warning.
- In situations where radar performance is compromised (as mentioned earlier).
- If an officer is visually spotted before radar targeting or within radar range.
- If an officer is spotted before they visually identify a speeding vehicle.
Situational awareness and a quality radar detector are key to maximizing the chances of avoiding radar-based speeding tickets.
Outbraking Instant-On Police Radar:
Example of outbraking an instant-on police radar trap with a fast acting radar detector
Contesting a Radar Speeding Ticket
Challenging a radar speeding ticket can be approached through several angles. One potential argument is questioning if the speed reading was accurately attributed to your vehicle in multi-car scenarios. While radar can target multiple cars, visual confirmation by the officer is required to identify the speeding vehicle, and errors can occur, especially with older systems not optimized for multiple target tracking. However, proving such errors in court can be difficult, as officer testimony is often given significant weight.
Another approach is to request proof that the radar gun was calibrated according to state regulations. While historically sometimes effective, officers today are generally well-trained and adhere to calibration schedules. A more viable strategy is to challenge the officer’s operating procedures. If there are grounds to believe procedures were not followed, a motion for discovery can be filed, requesting officer notes, dashcam footage, and bodycam video. This forces the prosecution to produce evidence, which can sometimes lead to the citation being dropped due to the effort required. Plea bargaining for a lesser offense or a non-moving violation is also an option, especially if the case against you is strong. Researching state statutes and alternative charges is advisable.
Radar Jammers: Legality and Effectiveness
Using police radar jammers is a federal offense. Historically available radar jammers have been of poor quality and ineffective against modern digital police radar. Currently, no effective radar jammers are known to be in production. In contrast, laser jammers are used to counter police laser, although their legality varies by jurisdiction.
Strategies to Avoid Radar Speeding Tickets
Key strategies to avoid radar speeding tickets include:
- Adhering to speed limits.
- Maintaining situational awareness.
- Using a radar detector.
- Utilizing navigation apps like Google Waze for speed trap alerts.
- “Rabbit” pacing: Following a speeding vehicle at a safe distance (though potentially risky and inconsiderate).
- Familiarizing yourself with common police radar locations in your area.
- Understanding the types of speed enforcement technologies used on your regular routes.
Police Laser vs. Radar
Police laser guns offer stealth and rapid speed acquisition, similar to Instant-On radar, but with the advantage of targeting specific vehicles precisely, like a sniper. Unlike radar, which can be less precise in heavy traffic, laser allows officers to target individual vehicles even in crowded conditions. Laser beams are highly focused, making detection by other drivers’ detectors challenging. Often used at longer distances, police laser is a highly effective enforcement tool. The combination of Instant-On operation and minimal warning makes police laser a significant threat.
Effectiveness of Police Radar Detectors
While no countermeasure is foolproof, high-performance radar detectors are very effective. Modern detectors have excellent sensitivity, providing ample warning against Constant-On radar, even from concealed positions. However, Instant-On radar, especially from moving patrol cars, can be more challenging. Familiarity with a radar detector’s alerts and operational nuances is crucial for maximizing its effectiveness.
Detecting Radar Detector Use by Police
For decades, police in areas where radar detectors are illegal used radar detector detectors (RDDs) like the Spectre to identify radar detector emissions. However, the manufacturer of Spectre RDDs is no longer in operation, reducing their prevalence. Currently, officers often rely on behavioral cues to spot radar detector users. Sudden braking upon being targeted with Instant-On radar can signal radar detector use to an observant officer.
Avoiding Speeding Tickets: A Proactive Approach
Investing in a quality radar detector combined with a laser detector and using a countermeasure like Laser Veil anti-laser coating is a comprehensive approach to avoiding speeding tickets. Veil can transform a radar detector from simply a ticket notifier to a ticket avoider.
Remember, always drive protected!
