OT Motorway speed cameras

[ARW]

Just got a NIP for doing 86MPH.

That is the speed I have passed them all for the last 10 years.

Did they turn them on last week?

[Andy Burns]

Not in one of the "speed limit for air quality" sections?

[alan_m]

Or perhaps the speedo was more accurate on the vehicle you were driving at the time. On previous cars I've owned the speedo was always reading approx 10% low at 70 mph (compared to GPS info) so on motorways I considered a speedo reading of 77 + 5 mph to be relatively safe for speed cameras. I'm not sure about the accuracy of the speedo in my current car as the inbuilt SatNav doesn't indicate a road speed.

[alan_m]

Are not they flagged up as 60 mph?

[Harry Bloomfield, Esq.]

alan_m formulated on Monday :

Speedo reading high - I think you meant.

[alan_m]

yes...

[Tim+]

Um, that?s illegal and highly unusual. Far more normal for speedos to over-read by 10%. At an indicated 77 you?re doing 70mph. (Probably what you meant though). ;-)

Tim

[The Natural Philosopher]

Mmm. My car was reading 10% high at 70mph until new tyres were fitted to the rear. Now its only 4%....

86mph indicated is a bit pushing ones luck I feel.

[Andy Burns]

mine reads 1-2 mph high whether at 30, or at 70.

[Andy Burns]

On the M1 between Leicester and Nottingham, I will say that previously I've exceeded that day after day with no issue, but covid means I've only done the journey every couple of months.

I've noticed local authorities have snuck in plenty of 60->50, 40->30 speed limit changes since March, maybe motorway plod has made changes too?

[Brian Gaff (Sofa]

Maybe they just got recalibrated to actually be correct? Brian

[Martin Brown]

It is a bad idea to pass any that you have spotted at much above 10% + 2 actual roadspeed.

Maybe your new vehicle's speedometer is more truthful.

Can you remember the indicated speed?

[Jethro_uk]

Not sure why you are surprised ?

Wait till the cameras for 20mph zones get set up.

[nightjar]

Perhaps this time there wasn't enough dirt on your number plate to confound the ANPR. :-)

[Dave Plowman (News]

The reason your inbuilt satnav doesn't give a speed readout is that most car makers deliberately make their speedo read high - taking advantage of the regs in this. The regs being from the days of making an accurate speedo an expensive business. These days pretty well all are pulse counting, and just as easy to make them far more accurate than the +10% allowed.

[Andy Bennet]

Problem is if measuring speed from tyre revs you can get a 12% difference between fully inflated and flat.

[Dave Plowman (News]

Quite. Be interesting to see how the next London mayor elections go. Given the draconian recent legislation against cars. Just a pity the Tory candidate is such a prat.

[The Natural Philosopher]

I doubt it is that much

[Chris Green]

Not that much surely, even when flat the tread doesn't skid much and the distance 'round the tyre' is still the same even when flat. It will make *some* difference because, presumably, the tyre expands a little when inflated but I doubt it's anything like 12%.

[Jethro_uk]

Who said anything about London ? This is nationwide.

Every single measure that I was told will be introduced to reduce speeding in 2014 has come to pass with 20mph zone cameras being the last.

As the instructors on my SAC course said: "Get used to not speeding, or get used to points".

Anyway, we long since passed the point where people won't vote against their own self interests. The current shitshow of a government busy shafting farmers and fishermen being a clear example.

And who, by the way, passed the "recent draconian legislation". Let me guess. Corbyn ??