Speed Camera Settings

[Dippo]

There's an article in today's Auto Express newsletter which gives the tolerance settings used by most police forces for their cameras:
UK speed camera tolerances revealed: is your car's speedo accurate?

 

[DoberMan]

Thames Valley has one of the highest no.of cameras. Thanks!
Although all may not be live at the same time if they are the old sort and not the new digital type.

What effect if any does having larger wheels have on the indicated speed?

My car has 20in wheels and I am conscious that the speedo reading maybe inaccurate.

Anyone know what apps can be downloaded to check speed?

I don't have a sat nav.

 

[clk320x]

Thames Valley has one of the highest no.of cameras. Thanks!
Although all may not be live at the same time if they are the old sort and not the new digital type.

What effect if any does having larger wheels have on the indicated speed?

My car has 20in wheels and I am conscious that the speedo reading maybe inaccurate.

Anyone know what apps can be downloaded to check speed?

I don't have a sat nav.

I believe all cameras are now digital

 

[artyman]

I ended up doing a speed awareness course for 34mph! so much for the 10%+2mph

 

[23 Romeo Tango]

My car has 20in wheels and I am conscious that the speedo reading maybe inaccurate.

Anyone know what apps can be downloaded to check speed?

When I had my winter 19's on I occasionally used the 'Speedometer' app to check my actual speed. It's not going to be deadly accurate, but it gives you a good idea of a cross reference against your dash reading. Handy on motorway average speed zones where you can tweak an extra 4 mph and get to your destination 20 second faster, not a great benefit but it makes you feel better.

 

[GeordieN]

On larger wheels your tyre side wall will be smaller so overall wheel and tyre combination should be the same, normally you would stay within 5% of original wheel tyre diameter. there are online sites that you can put in your existing wheel tyre set up in and your new larger wheel tyre set up and it will tell you difference in size and speed between the two set ups.

On the 34mph in a 30mph limit, i have always thought the tolerance in a 30 zone was zero. since you were prosecuted under the tolerance listed I wonder if in a 30 zone you only get the 10%. Has anyone been pulled for speeding between 31mph to 33 mph ?

 

[DoberMan]

I ended up doing a speed awareness course for 34mph! so much for the 10%+2mph

So did I !

 

[BMF]

If I know there is a speed camera that I am approaching I will drop my speed to just under 30 (in a 30mph zone) and just under 40 (in a 40mph zone) etc.

If I am travelling through an average speed camera zone, I make sure to set my cruise control to just under the sign posted speed for the section.

It is a source of amusement that other road users pass me in these sections like I'm going backwards. I don't think you can take it for granted that there is leeway on any camera system fixed, mobile or average.

 

[Teego]

If I know there is a speed camera that I am approaching I will drop my speed to just under 30 (in a 30mph zone) and just under 40 (in a 40mph zone) etc.

If I am travelling through an average speed camera zone, I make sure to set my cruise control to just under the sign posted speed for the section.

It is a source of amusement that other road users pass me in these sections like I'm going backwards. I don't think you can take it for granted that there is leeway on any camera system fixed, mobile or average.

Cameras or not I always use my limiter in 30s, also in 40s which I don't know, sometimes in AS camera zones such as motorways.
The Cat & Fiddle Pass is a 50 zone supposedly controlled by AS cameras. In fact you can press on quite well on the open stretches as the bends will drag down your average. If you want to go batshit there are laybys to sit in and slash the average.

 

[190]

In the Auto Express article it was interesting to note how accurate speedo's are in modern cars. Given the law, they are obviously calibrated to over read so that at 30MPH your real speed is 28 or 29MPH but the consistency throughout the speed range is remarkable demonstrating that they could make speedo's read spot on if they wanted to. Based on road side radar displays, my own speedo seems similar to those tested reading no more than 1 MPH high throughout the range.

 

[ToeKnee]

The Speedo on my insignia is way out compared to actual speed travelled.

 

[Bellow]

The Speedo on my insignia is way out compared to actual speed travelled.

That has been said of Vauxhalls (and Hondas) for decades. When the odometer also over-reads, it flatters the mpg.

 

[ToeKnee]

That has been said of Vauxhalls (and Hondas) for decades. When the odometer also over-reads, it flatters the mpg.

Didn't know that, this is my first, and last ever, Vauxhall!

 

[Bellow]

Didn't know that, this is my first, and last ever, Vauxhall!

Could be an urban myth of course...
I was told about Vauxhalls when Corsas were popular with the youth - the over-reading of speed being why. Not sure I even believe it!

 

[BTB 500]

In the Auto Express article it was interesting to note how accurate speedo's are in modern cars. Given the law, they are obviously calibrated to over read so that at 30MPH your real speed is 28 or 29MPH but the consistency throughout the speed range is remarkable demonstrating that they could make speedo's read spot on if they wanted to.

Tyre wear reduces the overall diameter, so even if the displayed speed was spot on with new tyres it would be over-reading (slightly) by the time they were down to minimum tread. All three of our vehicles typically over-read by 4-5 mph at motorway speed (against a GPS).