Youths Give A Speed Camera Van Some Probs

[Velvet Glove]

They use laser, not radar

[Velvet Glove]

Hey Velvet Glove, that's a crock, I have seen a sh*t load of mobile cameras that run with one operator, as a matter of fact I saw one today.

Anyway, "you an officer of the law" and if I dont agree I will be arrested and cornholed

Just a joke!

Zak

As was said, that may be the case in Qld but here in the ACT they operate with a minimum of 2

[saleen]

Does a speed camera take a pic of your car from the back or the front? I'd be worried that they put the number plate on the wrong end. Unless the urban myth is supposed to read they took both plates.

[mickq]

In just about every state (in fact, as far as I know it does apply to every state), mobile speed cameras use RADAR.

They do not use LIDAR (aka Laser) as the technology is not at the level yet where this can be easily done. Its not as easy as you may think to make a pinpoint LIDAR unit hit a car it doesnt know is there! Unlike RADAR you cant just "shine" it all over the place, say in a search pattern until it gets a hit, because LIDAR is harmful to your eyes, so doing so places the public at risk. (The way around it is to mix LIDAR with a RADAR target finder, but then if you have radar you may as well just use RADAR only)

Currently the only LIDAR being used are hand held units that some cop cars have in them. (Some still have the older RADAR handheld units).

Speed camers mounted in cars/vans etc use RADAR. In the old days (and some other countries) you could also find them linked to two rubber hoses run across the road, and this was called an amphometer.

They can take your photo from the front or back. Usually it is the back, but the useless taxation agent sitting in the car has a switch he can flick that will set the unit to measure cars travelling in the opposite direction if needed. (They flick the switch if they see a person really hooning towards them, and if it seems unlikely a car on their side of the road will block the photo).

Hand held speed measuring units (not cameras) use RADAR or LIDAR. Radar is limited in distance (max 300-400m on an empty road) and also effected by traffic density (ie busy traffic means you cant accurately determine the speed of one single vehicle). LIDAR spreads to only 4 inches at 1km, so they can get you from a long way away even in heavy traffic. Ive been caught by laser from 1313m away.

Fixed speed cameras (inlcuding ones on Vic's CityLink and also Redlight Speed cameras in Vic) use wires in the road. These come in two flavours: electromagnetic field detectors (like whats used to determine a car is waiting at an intersection for the lights to change) and piezo electric loops, which when run over and compressed cause a voltage to be created. Both of these methods require two or three (usually three) loops or wires in the road a certain distance apart in order to determine the time taken to travel that distance. (And interestingly, as the road cools and heats it expands and contracts...altering the distance and thus the speed the device thinks it measures. This screws many people caught for 3 over the limit in Vic when in fact they may not have been. Vicroads refuses to hand out the road contraction and expansion data as they know the trouble it will cause!)

PS, the story is true as I remember when it hit the news. The only think Im not sure about is which state it occurred in.

Edited 25/01/04 02:49 PM by mickq

[Velvet Glove]

Of course if it was in the news then it must be true !

If a speed camera van had its plates pinched and someone drove through it 14 times then the plates wouldnt match the vehicle and no TIN would be issued. Worst case if that the speed camera operators would be given a 'please explain' and their operators log would clearly show that when the happy snaps of their plates were taken, they were stationary doing their job.

There is no 'automated billing system' from my understanding. It didnt happen in Canberra

[KrasH]

Like I said, I suspected it was an urban myth.. Too good to be true syndrome..

In the day time the camera vans in Canberra are easy to see. Sucks though that they also work at night with infra red.. doh (haven't been caught yet though *touch wood*).. I remember hearing that the camera vans can get 1 car per 3 seconds, but I would suspect that it could be more like 3 cars per second. I remember the news stories when they first started using the vans here, but I can't recall if they said radar or laser.. oh well..

[Velvet Glove]

I have spoken to many camera van operators and they have told me how surprisingly few drivers they actually get. They have told me that they often sit at a site for 30 mins and might only 'get' 1 or 2. The greater majority of them park in pretty obvious places and you can get their locations via the ACT Govt website.

If you have one of those GPS things we had a comp for before (forgot what they're called AGAIN !) then you can program all their sites into the machine unless they're already there.

Speed cameras can snap your front or your back plate, depending on how they're set up. The device that measures the speed, be it laser or radar, can tell how fast you are either coming towards it or going away from it.

On the roads I regularly drive, like Phillip Ave in Downer, I know where they set up all the time so I keep a good eye out. Many Canberrans would think likewise.

[KrasH]

You certainly do get used to where they may be parked. Some of the regular spots I've noticed in my part of town. Barton Hwy (near the new bridge towards yowani), Gunghalin drive just before Palmerston, sometimes further up towards the school. Northbourne avenue. Especially around the Yowani Part. Phillip Ave in Watson is maybe the street in Canberra you have to look out for. I remember years ago, before the Camera's that police were usually parked there ready and waiting. Fortunatly for me I notice them and take care especially where I see them even once.