NIP m25 variable 50. Bugger.

[Phatboy317]

Devil2575 said:

Phatboy317 said:

I'd be very interested to see the mathematics

Why? You probably wouldn't understand it and start waffling about how you'd have missed the traffic jam altogether if you'd been going faster...

I'll take that from whence it comes

But seriously...

[richardrsc]

loafer123 said:

Surely going from 60 to 30 is extremely common - why are they struggling with 70-50? Poor observancy?

It's not really a good idea to rapidly slow from *0-50 when the roads clear ahead and there's a car behind you. I don't know if the guy behind me has seen it, or has any intention of slowing.

I tend just to ease off rather than slamming the breaks on. Obviously this is the incorrect manoeuvre!

[richardrsc]

speedyguy said:

A bit left field and I'll probably get flamed

Maybe the 50's are put up automatically worked out by the MIDAS loops in the road surface (or being the M25 the new laser measurement devices) and algorithmic mathematics to smooth the traffic flows down to keep traffic flowing steadily rather than the stop/go phantom queues of the old days as they know what is happening a couple of miles ahead out of your field of vision

There again i could be talking complete bks

I don't doubt that there's an element of that somewhere, but I regularly do the m25 and I've been on it when its really clear at 9 or 10 at night, and its randomly going from 40,50,40,60,nsl,60,50 for no reason at all. It's no wonder people ignore it.

[richardrsc]

V8 Fettler said:

Where on the M25 were you captured?

jnc 18-17 anticlockwise 19.50pm

[richardrsc]

speedyguy said:

A bit left field and I'll probably get flamed

Maybe the 50's are put up automatically worked out by the MIDAS loops in the road surface (or being the M25 the new laser measurement devices) and algorithmic mathematics to smooth the traffic flows down to keep traffic flowing steadily rather than the stop/go phantom queues of the old days as they know what is happening a couple of miles ahead out of your field of vision

There again i could be talking complete bks

So speedy - you're going along at , lets say 80 in the outside lane. You check your mirror and have someone fairly close to your tail. You see the limit ahead change to 50 a hundred meters out.

Do you

A. Ease off the accelerator.
B. Slam on the brakes.

[bad company]

richardrsc said:

So speedy - you're going along at , lets say 80 in the outside lane. You check your mirror and have someone fairly close to your tail. You see the limit ahead change to 50 a hundred meters out.

Do you

A. Ease off the accelerator.
B. Slam on the brakes.

You could change lane then slam on the brakes - obviously that only works if the lane on your left is clear.

[Magic919]

You don't need to react if it changes when you are 100 metres away.

[richardrsc]

Magic919 said:

You don't need to react if it changes when you are 100 metres away.

Do you not? Please can you refer me to the law that says that?

[richardrsc]

bad company said:

You could change lane then slam on the brakes - obviously that only works if the lane on your left is clear.

Ok, for arguments sake, the middle lane is full of Nissan Micras doing 62 miles an hour like normal.

I think what I'm trying to get at, is that slamming on the breaks for any reason on the motorway when there is no immediate threat ahead is silly. Easing off is, in my view, the sensible option. However doing that gets you 3 points and a fine.

Edited by richardrsc on Saturday 18th April 11:33

Edited by richardrsc on Saturday 18th April 11:34

[Devil2575]

richardrsc said:

So speedy - you're going along at , lets say 80 in the outside lane. You check your mirror and have someone fairly close to your tail. You see the limit ahead change to 50 a hundred meters out.

Do you

A. Ease off the accelerator.
B. Slam on the brakes.

False dichotomy. Neither, I'd brake gently to start with increasing once I'm sure the car behind has clocked me. Simply easing off doesn't light up the brakes so the car behind is less likely to notice you slowing, at least initially.

[richardrsc]

Devil2575 said:

False dichotomy. Neither, I'd brake gently to start with increasing once I'm sure the car behind has clocked me. Simply easing off doesn't light up the brakes so the car behind is less likely to notice you slowing, at least initially.

At 80mph, you are travelling ~36 metres a second. You have under 3 seconds in which to pass that gantry at the 50 limit.

You spend the first 1.5 seconds breaking and waiting to see if the car behind you is slowing. Now you really hammer the breaks on?

The road ahead is clear.

[SS2.]

richardrsc said:

Magic919 said:

You don't need to react if it changes when you are 100 metres away.

Do you not? Please can you refer me to the law that says that?

The M25 Motorway (Junctions 16 to 23) (Variable Speed Limits) Regulations 2013

[SS2.]

richardrsc said:

At 80mph, you are travelling ~36 metres a second. You have under 3 seconds in which to pass that gantry at the 50 limit.

If the 50 limit had just flashed up, you would be clear of the gantry before the new limit was in effect.

[Devil2575]

richardrsc said:

Devil2575 said:

False dichotomy. Neither, I'd brake gently to start with increasing once I'm sure the car behind has clocked me. Simply easing off doesn't light up the brakes so the car behind is less likely to notice you slowing, at least initially.

At 80mph, you are travelling ~36 metres a second. You have under 3 seconds in which to pass that gantry at the 50 limit.

You spend the first 1.5 seconds breaking and waiting to see if the car behind you is slowing. Now you really hammer the breaks on?

The road ahead is clear.

You're trying to create a hypothetical situation to prove a point but I don't think it's valid. You could equally create a similar hypothetical situation approaching a set of traffic lights, yet how often do people have to hammer the brakes to stop in time.

[robinessex]

In all the times I've been through the Heathrow Section (the first), I've never seen it work in the manner in which advocates say it should/will. I've encountered all the faults that others have reported. I'm staggered that the advocates of this technology have seen fit to spread it further around the M25. I'm firmly of the opinion that the master plan is to populate the entire M25 with some sort of average speed system eventualy. Now, where's that revolving numberplate website.

[richardrsc]

SS2. said:

The M25 Motorway (Junctions 16 to 23) (Variable Speed Limits) Regulations 2013

Ah, OK you win that one.

So that makes it even more difficult. Is the car behind going to stop? How long has the sign been active? Should I speed up to make it through within the 10 seconds? They need to put a countdown indicator on them to give us a sporting chance.

Edited by richardrsc on Saturday 18th April 14:50

[richardrsc]

Devil2575 said:

You're trying to create a hypothetical situation to prove a point but I don't think it's valid. You could equally create a similar hypothetical situation approaching a set of traffic lights, yet how often do people have to hammer the brakes to stop in time.

Honestly I can only assume you don't drive the m25 much if you can't see this situation - or you're a 60mph kind of guy anyway.

But regardless, so what's the best way to weasel out of it? The NIP was curiously indicates that I was snapped at precisely to the minute with no seconds. I wonder if they can back it up with a log of what time the display changed? And if the units are both synced to the same NTP server.

Yeh I know realistically I'll probably have to swallow it, but it's nonsense. As far as I'm concerned I was complying with the spirit of the law by not doing 80 like normal.

Edited by richardrsc on Saturday 18th April 14:47

[Funk]

I hate to be That Guy but this is a car forum; it's 'brakes' and 'braking'.

[richardrsc]

Funk said:

I hate to be That Guy but this is a car forum; it's 'brakes' and 'braking'.

You are that guy. Sorry!

[richardrsc]

Monkeylegend said:

This should put to bed the myth that these cameras are for show only.

To be fair, they clearly don't work very often. I'm not saying more than that.!