I have noticed a lot of threats where many inaccuracies have been posted about police and speeding. Therefore I have decided to provide this information to you to clear up these misconceptions. Take it from me as someone who has a professional involvement in these matters that this information is accurate-
Police can take action against speeding vehicles in a number of ways:
1. By use of a radar fitted to the police vehicle. In NSW at least, the model used is called a Silver Eagle. Its fitment to Highway Patrol cars is most easily distinguishable by a small radar "head" mounted either on the police vehicles roof light bar, or from an attachment on the drivers side passenger door. Unmarked vehicles also mount the radar head inside the vehicle on the dash at the base of the drivers side windscreen. There are other more unconventional methods of mounting and aiming the antenna, but these are uncommon enough not to rate a mention.
The radar can be used when the police vehicle is moving or stationary. When stationary, the radar will detect vehicles both approaching and departing ahead of where the radar head points. When moving, the radar will detect vehicles approaching only, and it calculates the speed of approaching vehicles by first establishing the speed of the police vehicle. When an approaching vehicle is detected by the radar it will get a closing speed, which is obviously the speed of the approaching vehicle plus that of the police vehicle. The radar then subtracts the police vehicles speed from that to display the approaching vehicles speed. The radar has a very long range.
2. By the use of a hand held laser gun known as a Lidar. This instrument can be operated by a police officer standing by the roadside or from the open window of a police vehicle. It cannot be used in a moving vehicle. This instrument can detect and display speeds of approaching or receding vehicles, and can easily measure the speeds of individual vehicles even in heavy traffic. The lidar also has a very long range.
3. By the use of a calibrated digital speedometer. Highway Patrol vehicles have a calibrated digital speedometer independent of the normal speedo. Naturally by definition it means its VERY accurate, and police can check the speeds of vehicles travelling in the same direction as the police vehicle by matching their speed and checking the speed displayed on the unit. If you are silly enough not to look whos behind you and you are speeding, this is what may cause your undoing.
5. Police vehicle mounted speed cameras. Basically they are semi marked police sedans and wagons (again in NSW at least) that are fitted with a radar which interfaces with a camera. The vehicles can only be used when stationary and set up correctly, and detect speeding vehicles approaching and receding to the front of the car only. They are almost completely automated and when set up, require almost no input from the police operator. They can be used in heavy traffic and can take happy snaps fast enough to make your head spin. The vehicle mounted speed cameras should not be confused with fixed pole mounted speed cameras which in NSW are operated by the Roads and Traffic Authority, completely independent of the police.
6. By estimation: Highway Patrol officers are trained to estimate speed by observation. Its normally done within a 10 km/h bracket. Their estimations are accepted by courts as expert evidence and optionally, this evidence can be backed up by speed checks from Lidars and Radars which are too short in time or otherwise not meeting guidelines for use of these instruments, but which still provide some evidentiary value as to the speed of a vehicle. Non Highway Patrol police can also estimate speeds of vehicles by their estimations alone, and/or by the use of the normal speedo fitted to non Highway Patrol vehicles when following speeding vehicles. Police trained in Accident Investigation can also use evidence from collisions such as skid marks, impact damage, and other things to make scientific judgements as to the speed of a vehicle prior to a collision.
A 10% tolerance with speed measuring devices applies, plus the error tolerance of the instrument used. This is between 2 and 3 km/h. So, you cant be booked (at least in NSW anyway) for any speed under say 68 km/h in a 60 zone. So dont believe what your friends, friends, cousin's hairdresser tells you about being booked for less.
So there you have it. There is more than one way to get booked for speeding. becareful out there kids!
