Safe Speed Forums

I noticed something.
The official statistics on number of vehicles and their speed on a road come from one of the grey telemetry boxes owned (usually) by the highways agency, right?

The same box is used for collecting data before and after the camera is installed.

As we all know, most people hit the brakes for the camera then speed up afterwards.

So...

Plonk the camera right on top of the telemetry box and magically the statistics show a huge decrease in the speed of vehicles on that road.

Have a look at the speed data at the bottom of the pages for these 2 cameras: (the speed limit for each site is at the top)
A351 Sandford Road, Sandford


Wareham Road, Corfe Mullen, Wimborne



On these two sites the camera and the telemetry data collection box are quite far apart. Plenty of room to change speed. Sandford camera shows a slight decrease in speed, Corfe Mullen one shows an increase! (err it is me or are the cameras meant to make people slow down?)

Put the camera slightly nearer the box and you get a more noticable change:
Fleets Lane, Poole


Put the camera "on top of" the data collection box and magically everyone has slowed down, wow!
A338 Wessex Way, Queens Park


Just another way to show how meaningful statistics are

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Andrew.

Great post Ziltro, indeed interesting to see in "black and white" how localised the effects of speed cameras are on the vehicle speeds. I don't know what the distances are, but I would reckon that most people only slow down for 100 to 300 metres around the actual camera in most cases.

And for the rest of the time all these responsible, careful, low-risk drivers have an extra distraction to worry about as they scan the horizon for cameras that are positioned at sites where the numeric speed limit has little relation to actual road safety .

Surely this is an excellent example of a system where badly motivated and poorly executed implementation has destroyed the trust of the public and thus removed any benefits the system was intended to facilitate.

Hmmm, I like that statement, think it deserves a separate thread...