time over distance speed cameras

[olly]

can any of you guys explain to me how those time distance speed cameras work?

let's say its 100kph freeway and there's a car that passes the first camera at only 80kmh and continues to go at 80kmh all the way to the next one. another car goes through the first camera at 100kph then speeds up and overtakes the car doing 80kmh then slows down to 100kph at the next camera.

how does the camera know which car was travelling how fast? the car doing 80kmh passed the first camera first but at the 2nd camera the other car was the first there. how can the camera tell the difference? what if theres heaps of cars that past it. surely some cars would be overtaken and so on, so how does it really detect which car has done which kmph?

it's really doing my head in as you can tell.. haha :lol:

 

[Richard]

They have the technology (pixies) that take a picture of your number plate and again as you pass through at the other end and if you have been traveling to fast over that distance they send you out a fine, so if you pass the first camera and stop for 10mins you could theoretically speed for the rest of your journy but there is still gonna be cops with radar guns to catch you!

 

[olly]

so doesnt that mean someone will have to look at ALL the numberplates and determine which ones were speeding and so on?..

 

[p3akin]

does anyone know where these cameras are located?

 

[olly]

most of em in vic are one hume hwy

 

[CLuTZ]

so doesnt that mean someone will have to look at ALL the numberplates and determine which ones were speeding and so on?..

yes.

 

[Dean]

Speed = Distance / Time.

Therefore if you know the distance (which is fixed)
all you have to work out is the time it takes you to get there (dunno how they work that out)
to work out if you have been speeding or not.

Year 11 physics...cmon bro haha

 

[lefty]

I remember physics a bit...

You can never travel at a constant speed.

You are always accelerating due to friction.

Closest thing to travelling at a constant speed is to be driving on ice.

 

[art]

I think this is how they will work.
Neither camera measures your instantaneous speed, like the normal road side radar speed cameras do.
The time distance cameras work by the 1st camera taking a photo of every number plate that goes past it, and recording the time of the photo and using a computer with optical character recognition to read each number plate. Then the 2nd camera takes a photo of every number plate that goes past it , and records the time and works out the rego number by OCR, then the computer compares the time each rego plate took to travel the distance between the two cameras. If the speed limit is 100km/h and the cameras are 100km apart and a rego plate appears at the second camera in less time than one hour, the rego owner will be fined.

 

[p3akin]

yeah what art said.. thats what i was thinking but didn't know how to word it.. read it in the sun awhile back

 

[JayRome]

its like the E-Tag system only on steriods and it can screw you over for speeding..... although i see glitches in there system, and a hell of alot of people complaining.... considering there is 5km or so leeway on every car's Speedo, fuked if i know how they will find a average speed from point to point unless they were to test every single car in australia!....

i dont think they have posted were there cameras are atm, but think of it, it would require a long stretch of road with no entrances or exits for monitoring purposes. soo if the next exit is 10km away and there are no entrance slip lanes...... and you seem to be passing a very large over head road signs... well duh thats were they are......

 

[GVR40]

Speed = Distance / Time.

Therefore if you know the distance (which is fixed)
all you have to work out is the time it takes you to get there (dunno how they work that out)
to work out if you have been speeding or not.

Year 11 physics...cmon bro haha

time=distance/speed, therefore it is safe to assume that if the distance is 10km and the speed limit is 100km/h then it should take you 6 minutes to travel from one camera to the next, if you get there faster than this then it is also safe to assume that you are travelling faster than the posted speed limit and hence you will get a fine

 

[Gav]

So you either get James Bond style number plates :lol:

Or you go past the first camera at 200kph and then stop before the
second camera and work out how long to wait until your average speed is
back to the speed limit

 

[GVR40]

basically

 

[brisvr4]

Or just don't speed between them :wink:

 

[Dean]

or just take another god damn road!!
lol

 

[Entaran]

They take a photo at point a and another photo at point b.

A computer matches general car colour and numberplates, then compares its recorded time from point a to point b (at 108kmh) against your time (which it timed from first photo time to second photo time) and if you get there faster you were obviously going 108+ and get a fine for the average speed you were doing.

They are worked out at 108kmh between point to point to allow a general overtaking margin and speedo correction.

 

[lefty]

or use no numberplates

 

[vsthis]

They take a photo at point a and another photo at point b.

A computer matches general car colour and numberplates, then compares its recorded time from point a to point b (at 108kmh) against your time (which it timed from first photo time to second photo time) and if you get there faster you were obviously going 108+ and get a fine for the average speed you were doing.

They are worked out at 108kmh between point to point to allow a general overtaking margin and speedo correction.

I wonder if harlaquin (however you spell it) paints will confuse the computer? Say if in one photo your car is green and in the next photo your car is purple, will it still match your nuber plates?

 

[vsthis]

Does anyone know if the cameras pick you up in the emergency lane?