The list of modifications you can make to your car to get the attention of the police is quite long, and often resulting in a vague fine in the hundreds.
However, there are very few things that are so explicitly written into the legislation, and you’d instantly be pulled over the second you pass a Highway Patrol vehicle, much like a radar detector.
So, what are they, why are they so easily detectable, and why are they illegal?
What is a radar detector?
In its simplest terms, a radar detector does as the name says – it picks up on the radar and lidar waves emitted from speed-measuring devices. Think of it as Waze on steroids. It senses speed-checking equipment and starts beeping.
Historically, they have worked by sensing the X, K, and Ka band (labels used for the frequency of signals) waves sent from a speed-measuring device. While radio systems can be complex, in layman's terms it uses what’s called the Doppler effect – bouncing those radio waves off oncoming cars and then receiving the change in frequency when it hits the targeted car. The gun can calculate the change in frequency and convert that into a displayed speed.
However, speed-measuring equipment has undergone significant improvements since the 1960s, when radar detectors first emerged onto the market. Now the police use something called lidar, which pulses laser light at 30 nanoseconds and a much narrower frequency but still with the same concept.
Radar detectors work by using a superheterodyne receiver, a type of radio receiver that was initially developed for Morse code machines. In its simplest terms, it works like a radio when you press the seek button only at higher frequencies. It’s constantly looking for those high-frequency waves, and when some bounce off the car ahead of you or you have it directly pointed at you, it will begin beeping.
Now there are lidar detectors, but the most commonly found one is actually a jammer. These work by mounting a receiver to the front of the vehicle that detects the laser signal, and it emits interference in the infrared light spectrum and 'jams' the lidar gun by not allowing a correct read, also while signalling the driver that it has been hit with a lidar gun.
Are radar detectors and jammers illegal in Australia?
Radar detectors are illegal in all states and territories of Australia. New South Wales was the first to outlaw them in 1987, while Western Australia only banned them in 2020.
The fines are massive too. Some states impose fines in the thousands for even owning one, let alone having it installed on your car.
New South Wales has several fines that can accumulate and be applied concurrently. Sell/offer for sale/purchase a vehicle with speed evasion article, responsible person vehicle driven with speed evasion article, responsible person vehicle stood with speed evasion article and fail to surrender speed evasion article, all are $2204 fines each.
That “responsible person” fine means that not only the person driving the car gets the fine, but also the person who owns the car and the device also gets fined (if it's not your car).
There is also a separate fine for being the driver of a vehicle, which sees nine demerit points and a $2204 fine.
In Victoria, it is illegal to own, sell, or offer sale of a speed-measuring evasion device. Having one will score you a fine of up to 20 penalty units, which is $4070. They can also get you for “failure to surrender speed-measuring evasion device", which is a $1017 fine.
Queensland will impose a fine of up to $6452 for anyone driving a vehicle equipped with a radar detector.
South Australia sees a more lenient approach. Driving with, possessing or selling a radar detector results in a $530 fine for each of the three.
Western Australia imposes seven demerit points and a $1200 fine for speed-measuring evasion devices in cars, while heavy vehicles get hit with $1500 and seven demerit points.
The Northern Territory imposes a maximum penalty of 40 penalty units, which translates to $7560.
The Australian Capital Territory will slap you with a fine of up to $3200.
Tasmania has a fine of up to 10 penalty units, which equals $2020.
How do the police detect radar detectors?
A large number of police vehicles are fitted with what’s called a radar detector detector (RDD), which picks up the signals that radar detectors unintentionally emit when they are scanning for those X, K and Ka bands we mentioned earlier.
An RDD works exactly the same as a normal radar detector, just at the frequency that picks up those oscillating waves emitted by scanning detectors.
Otherwise, lidar jammers are easily detected due to the guns being a fairly reliable piece of equipment. If it's throwing error signals when the Highway Patrol point it at you, there’s a good chance you’ll be pulled over and have your car looked over.
Zane Dobie comes from a background of motorcycle journalism, working for notable titles such as Australian Motorcycle News Magazine, Just Bikes and BikeReview. Despite his fresh age, Zane brings a lifetime of racing and hands-on experience. His passion now resides on four wheels as an avid car collector, restorer, drift car pilot and weekend go-kart racer.
