People breaking average speed limits on M-ways - how?

taxiphil

The other night I was driving through the long stretch of 50mph "road works" with average speed cameras on the M6 in Birmingham.

I was doing a constant 50, and in the space of about 10 miles I counted 14 vehicles shooting past me.

Before anyone says my speedo is obviously wildly inaccurate, I regularly compare it to my sat nav's reading on long stretches at constant speed. So I was doing 52 (on cruise control) according to the car's speedo, which my sat nav says is 50.

But these vehicles weren't just creeping past me, they were bombing it, clearly well in excess of 65 and some nearer the 80 mark.

So what's the deal here?

I can only assume that either:
a) They're on false plates, or have somehow registered the vehicle fraudulently
b) They're privy to some kind of insider information that these cameras are not currently functioning (or are inactive at certain hours of day - this was 11pm btw)

Any other theories?

paddedjohn

How about c) they will wake up one day to a ticket through the post.

taxiphil

paddedjohn wrote: »

How about c) they will wake up one day to a ticket through the post.

It did cross my mind, but are that many people really that stupid? Are their licences that unimportant to them?

sithmaster

taxiphil wrote: »

It did cross my mind, but are that many people really that stupid? Are their licences that unimportant to them?

properly not what they do is speed first then come on here later asking how to appeal it

cubegame

See it all the time on the A23 roadworks. The usual suspects also brake for the cameras. It's simply that a large percentage of people don't know what average means.

alanrowell

d) Cameras not turned on

worried_jim

Can you still change lane when you go through the cameras or is this an urban legend?

RichardD1970

worried_jim wrote: »

Can you still change lane when you go through the cameras or is this an urban legend?

Urban myth.

roddydogs

alanrowell wrote: »

d) Cameras not turned on

So how would they know if they wernt turned on?

Aretnap

taxiphil wrote: »

It did cross my mind, but are that many people really that stupid?

One or two apparently

http://www.cambridge-news.co.uk/Cambridge/More-than-4000-snared-by-latest-A14-speed-cameras-between-Girton-to-Fen-Ditton-20140111060500.htm

Prothet_of_Doom

taxiphil wrote: »

The other night I was driving through the long stretch of 50mph "road works" with average speed cameras on the M6 in Birmingham.

I was doing a constant 50, and in the space of about 10 miles I counted 14 vehicles shooting past me.

Before anyone says my speedo is obviously wildly inaccurate, I regularly compare it to my sat nav's reading on long stretches at constant speed. So I was doing 52 (on cruise control) according to the car's speedo, which my sat nav says is 50.

But these vehicles weren't just creeping past me, they were bombing it, clearly well in excess of 65 and some nearer the 80 mark.

So what's the deal here?

I can only assume that either:
a) They're on false plates, or have somehow registered the vehicle fraudulently
b) They're privy to some kind of insider information that these cameras are not currently functioning (or are inactive at certain hours of day - this was 11pm btw)

Any other theories?

I'd be surprised if you estimated the speed that they passed you at correctly.
Stand by the side of a road where the traffic is doing 30 MPH, judge a distance by the point that a cars number plate becomes blurry, and when a car goes past count in thousands from the time it passes you until the point you can no longer see the number plate correctly.

Then when you are on the motorway, see how long it takes for a car that is over taking you to disappear into the distance.

Typically when I tried this, those cars I thought might be doing 80, were probably doing 60, and those that I thought were doing 60, were probably doing 55.

Given that they are average speed cameras, and that they have a known degree of accuracy, which might come from weather conditions, which lane the car is in, measurement drift internally, (going out of calibration), calibration errors, etc, they are likely to be set "points safe". That is: They identify false negatives, becuase to identify false positives would be giving people points they don't deserve.

I don't know where they are set, but I reckon as high at 60 mph.

I don't take the risk. I have 3 points, (think of the kittens that died when I was done at 58 about 50 metres after the 50 sign, just 1 mile from the end of the M62, whilst I was braking to 50, on a dry sunday afternoon), and I'm not not sure I understand why others take that risk.

1) Stupidity.
2) False plates or a pool car registered through a company which has poor record keeping.