M1 Nottingham Specs Cameras In Roadwork

[ashpilot]

Everytime I travel to work it involves passing through the M1 Road Works Between J27 and J26. These road works have a 50mph limit with specs average speed cameras enforcing the speed limit.

I usually set the car to 50mph using my roadpilot gps and put on the cruise control. So if i am using the gps speed which should be very accurate, why am I constantly being passed by various cars and the occasional lorry. Are these people going to get tickets through the post or do they know something I do not.

What are the tolerances of these average speed cameras?

Are they operational?

or is the road full of muppets with 3 points pending?

[tHomBleached]

presume they're the same as the yellow buggers (10%+2) Average one may be set with a bit more lee-way?

[dave1]

Some on the M25 were recently reset at a lower limit.....they were changed from 93MPH to just over 80 MPH.

I couldn't believe it!!

[Mike_B]

Some on the M25 were recently reset at a lower limit.....they were changed from 93MPH to just over 80 MPH.

I couldn't believe it!!

Is that right? Blimey, I'll have to be a bit more careful!

[dave1]

Some on the M25 were recently reset at a lower limit.....they were changed from 93MPH to just over 80 MPH.

I couldn't believe it!!

Is that right? Blimey, I'll have to be a bit more careful!

Not sure what the tolerance is when they are on the variable setting though

[shake]

i was on the m25 speed trap today, many cars passed me while i was doing the limit. sods law if i did it, id get a ticket!

[MacRS200]

There is a tolerance of +/- 10% allowed on a speedo, so if you set to do a very accurate 55 you will be OK. The extra + on top allows for a little bit of not paying too much attention to the speed rather than the road.

As a wierd fact your speedo is not part of the MOT and is not tested, but, to not have a working one on the road is illegal!

[GlynnB]

I didn't think that there was any negative tolerance allowed on a speedo only +10%. So that at 30 it must read between 30 and 33, and so manufacturers tend to go to the higher level so as not to fall foul of the lower limit.

[dave1]

As a wierd fact your speedo is not part of the MOT and is not tested, but, to not have a working one on the road is illegal!

When did that become law?

I remember years ago that the law was worded to the effect that a means of measuring vehicle speed must be fitted. I was told (in the '70s) that a rev counter did actually qualify by Traffic officers in Huntingdon.

[GlynnB]

How could a rev counter work?

For 2000 rpm it could be 10 mph in first, 20 mph in second, 30 mph in 3rd, 40 mph in fourth and 50 mph in fifth?

[Bazza]

As a wierd fact your speedo is not part of the MOT and is not tested, but, to not have a working one on the road is illegal!

When did that become law?

I remember years ago that the law was worded to the effect that a means of measuring vehicle speed must be fitted. I was told (in the '70s) that a rev counter did actually qualify by Traffic officers in Huntingdon.

its probably not checked as they have no means of checking it

[dave1]

How could a rev counter work?

For 2000 rpm it could be 10 mph in first, 20 mph in second, 30 mph in 3rd, 40 mph in fourth and 50 mph in fifth?

I assume that if you were within the speed limit you would not be stopped to check. Most people know what revs equate to certain speeds (and in different gears in their own cars) in much the same way as in a manual car you know when to change by engine note not by looking at speedo. I could certainly have driven in the 70's using the tachometer and keep to speed limits....and have done so back then in various cars. It was not uncommon for speedometer cables to break at that time.

[dave1]

How could a rev counter work?

For 2000 rpm it could be 10 mph in first, 20 mph in second, 30 mph in 3rd, 40 mph in fourth and 50 mph in fifth?

I assume that if you were within the speed limit you would not be stopped to check. Most people know what revs equate to certain speeds (and in different gears in their own cars) in much the same way as in a manual car you know when to change by engine note not by looking at speedo. I could certainly have driven in the 70's using the tachometer and keep to speed limits....and have done so back then in various cars. It was not uncommon for speedometer cables to break at that time.

[WylieCoyote]

The ACPO guidelines require all safety cameras to have a tolerance of 10%+2mph. This is to allow for any fluctuation in speedo readings as invariably they're a little bit out.

I wouldn't rely too heavily on GPS speed - it'd be affected by topography - it would likely tell you you were going slower than you were if you're up and down hills.

I'm afraid that anyone caught at 93mph deserves to be caught - even 80 is pushing it. Speed limits are there for a reason and until they're changed, there should be no need for anyone to exceed 70.

I do think the current fixed penalty thing is unfair though, someone gets caught doing 80 on an empty dual carriageway in the dead of night gets exactly the same punishment as a nutter doing 50 outside a school at closing time. That's not fair.

[MarkD]

Hate to say this ,but the average speed cameras on the roadworks between J26 and J27 are not operational. They have been mounted for Health and safety reasons while the widening is taking place. Although they do monitor traffic flow and potentail accidents/breakdowns, they are not calibrated on speed.