Police speed camera

[PeteMorris 10]

It's not an error. Speedos are generally set to overread slightly - so if you drive to what's shown on your speedo you should never be speeding assuming you have the right speed limit for that road.

 

That's a bit bonkers really. It's like having a cerntral heating thermostat that's 'wrong' so you don't use it as often!

 

Are you sure they're actually 'set' that way?

[stifflersmom 11]

It isn't bonkers to have the speedo calibrated high, its a safeguard to ensure manufacturers do not become liable for speeding offences. Speedos are devices subject to measurement error so it makes sense to calibrate them to account for the error.

[sedith 19]

It isn't bonkers to have the speedo calibrated high, its a safeguard to ensure manufacturers do not become liable for speeding offences. Speedos are devices subject to measurement error so it makes sense to calibrate them to account for the error.

But if its inaccurate one way, couldn't it be inacurate the other way? Why not just make it spot on! Surely they can do that if they can land a space module on Mars?

[Penfold70 10]

But if its inaccurate one way, couldn't it be inacurate the other way? Why not just make it spot on! Surely they can do that if they can land a space module on Mars?

 

 

 

 

They can't make or set them spot on because something as simple as changing your wheels/tyre combination can change the actual speed vs indicated speed relationship.

[armin 10]

But if its inaccurate one way, couldn't it be inacurate the other way? Why not just make it spot on! Surely they can do that if they can land a space module on Mars?

 

Why not make it stop on? Because the same speedometer must accommodate different wheel/tyre sizes and arguably tyre wear would affect the accuracy to some extent as well.

 

A largish wheel rotates less often than a small wheel, therefore would indicate a lower speed.

 

As modern cars are controlled by a computer, perhaps there's a setting somewhere for the tyre size? Wouldn't hurt to ask...

[lolli_pop 10]

That's a bit bonkers really. It's like having a cerntral heating thermostat that's 'wrong' so you don't use it as often!

 

Are you sure they're actually 'set' that way?

 

It's one of those "how accurate do you want it to be?". I'd rather have it set high than set low. Mine is off by just over 1 mph at 30 and 3ph at 70, according to my sat nav, which isn't a bad margin of error. And yes, I have been geeky enough to test the over-read (digital speedo, so I can get a reasonably accurate idea of the over-read).

[ANGELFIRE1 10]

They can't make or set them spot on because something as simple as changing your wheels/tyre combination can change the actual speed vs indicated speed relationship.

 

 

The voice of commen sense. What a refreshing change.

 

Angel.

 

ps. Of course "safety cameras" are all about collecting money, bugger all to do with anyone's safety. Slow down for sc, then accelerate back to the speed you were doing - EVERYONE does the same.

 

SPECS are the only camera designed for safety, IMHO of course.

 

http://www.speedcamerasuk.com/specs.htm

[Cyclone 10]

They can't make or set them spot on because something as simple as changing your wheels/tyre combination can change the actual speed vs indicated speed relationship.

 

You aren't supposed to change the rolling radius of your wheels though and if you did then the speedo can't be accurate no matter how it was set before hand.

Wear would increase the indicated speed vs real speed, but that's not a big deal as it only goes one way.

[blackrat 10]

I know someone who operates these speed guns for his job. He tells me that they can capture your speed at 2000 feet away. So if only noticed the van 250 feet away then he could have read your speed a lot further back than that.

[Amaranthus 10]

I know someone who operates these speed guns for his job. He tells me that they can capture your speed at 2000 feet away. So if only noticed the van 250 feet away then he could have read your speed a lot further back than that.

 

I believe you... I was caught by a speed trap on the motorway last week, I spotted him from about 300 yards away and applied the brakes but he still pulled me and showed me the reading on the speed gun, which was the speed I'd been travelling at before I saw him and braked.

[woodmally 10]

they are a way of taking those of us who broke the law. (i got caught by one.)

 

it is a voluntary tax though. i chose to speed.

 

Hats off for your honesty I wish other motorists would accept this argument and either pay up or dont speed instead of blaming the camera.

[dronboy 10]

Thank you all for your contributions. I always accept the consequences of my own actions if somewehat grudgingly as a grumpy old man. I have also been on the Speed Awareness Course as the result of a previous marginal decision.

However well we think we are driving it is difficult to always be within the limits.

However on this occasion me and my partner who was in the car are convinced we were on or below the limit and wondered if there were camera errors that day and if so there would be others in the same boat.

The comment about us being a little quicker before the roadside camera/van came into view may be valid but we were certainly around 40 because we checked as soon as we saw it.Also the radar would have to target us out of site as there is a curve in the road.

It's not just the fine of course but knock on for insurance when you have no existing penalty points - all for alleged 46mph when other contributors tell us speedos are 2/3mph fast and ACPO is 10% + 2mph!and we're convinced we're within limit.

Ah well - face it like a man.