A couple of questions about gantry signage and speed limits

TooManyPoints

I don't get how any gantry or temporary speed limit is enforceable, unless there is a photo of the vehicle speeding and the sign.

If I get a speeding ticket, how can innocence or guilt be proved either way?

National Highways keep a log of all VSLs imposed, when they began and ended. To prove your guilt when you were detected by camera, the prosecution would have t satisfy the court of:

1.The vehicle involved

2. Who was driving it

3. The speed alleged

4. The prevailing limit.

(1) Would come from a photograph taken by the camera

(2) Would come from your response to the "Request for driver's details"

(3) Would come from the measuring system associated with the camera

(4) Would come from either the simultaneous photograph of the gantry sign or the National Highways' log.

When a variable speed limit is imposed enforcement must not begin until ten seconds after its imposition. In practise at most sites a longer "grace period" of up to on minute is allowed.

Car_54

[Deleted User] said:

What's the etiquette for letting people who leave it late into your lane?

If they are polite and don't barge I might allow it, but if it's an SUV/BMW/Audi... No way.

“Etiqutte” is a bizarre concept. 

What matters -should things go wrong - are safety and the law. The Highway Code is a good starting point. Rule 168 tells you to drop back and maintain a two-second gap.

Remember - failing to keep a two-second gap is much more likely to kill you than the other guy!

la531983

Grumpy_chap said:

I am actually with the OP on this one.  If the gantry signage reads 40 mph and there is no signage to revert back to NSL, then the limit remains 40 mph.

And what about the people who join at all the junctions afterwards, they can happily go NSL whilst the OP has to pootle along at 40? Utterly nonsensical logic.

How long would you be happy to continue to drive at 40 without any repeaters in that scenario? Ten miles? Twenty? All the way round to the Dartford bridge/tunnel? 

Grumpy_chap

la531983 said:

Grumpy_chap said:

I am actually with the OP on this one.  If the gantry signage reads 40 mph and there is no signage to revert back to NSL, then the limit remains 40 mph.

And what about the people who join at all the junctions afterwards, they can happily go NSL whilst the OP has to pootle along at 40? Utterly nonsensical logic.

How long would you be happy to continue to drive at 40 without any repeaters in that scenario? Ten miles? Twenty? All the way round to the Dartford bridge/tunnel? 

You selectively edited out an important part of my post about possible missed signage and using judgement:

Grumpy_chap said:

I am actually with the OP on this one.  If the gantry signage reads 40 mph and there is no signage to revert back to NSL, then the limit remains 40 mph.  It is possible that the OP missed the NSL sign, or just that gantry was out for some reason.  There comes a point where you have to take a judgement call that you did miss the NSL sign and then speed up but I doubt that would stand up in court.

I think, taken as a whole, the meaning of my post is rather clearer.
There is no set distance at which continuing to drive at the reduced limit ends.  Like everything with driving, it is a matter of assessing the conditions at the time and acting prudently.

la531983

In my mind it would be after two gantries with absolutely nothing on them. Other mororists appetite for risk may not be as great as mine, if they want to go 40mph needlessly for miles they can crack on 

Grey_Critic

From which junction? There are aroad works from around J41 M1 right through to Leeds and M62 J24  through to just short of J30 and 40mph restrictions plus the gantry cameras are live withh average speed cameras. Everything is well signed. I use both fairly regular and did so on Wednesday

la531983

Grey_Critic said:

From which junction? There are aroad works from around J41 right through past J29 and 40 mph. When a sign says get over then I suggest you do so. The gantry cameras are live plus average speed cameras

The M25 doesn't have a J41.

He says J17 in the opening post. 

sevenhills

TooManyPoints said:

(4) Would come from either the simultaneous photograph of the gantry sign or the National Highways' log.

That is good to know, but what about signs at the side of the road?

Highways say there was a sign, but can I go and look to see if it's still there?

born_again

[Deleted User] said:

What's the etiquette for letting people who leave it late into your lane?

If they are polite and don't barge I might allow it, but if it's an SUV/BMW/Audi... No way.

As per HWC..

Merge in turn. 

Hate the fact drivers sit in one lane while another is empty, you can use both lanes till lane is blocked. Causing longer tailbacks.

boxosox

Car_54 said:

sevenhills said:

Grumpy_chap said:

I am actually with the OP on this one.  If the gantry signage reads 40 mph and there is no signage to revert back to NSL, then the limit remains 40 mph.  It is possible that the OP missed the NSL sign, or just that gantry was out for some reason.  There comes a point where you have to take a judgement call that you did miss the NSL sign and then speed up but I doubt that would stand up in court.

I don't get how any gantry or temporary speed limit is enforceable, unless there is a photo of the vehicle speeding and the sign.

If I get a speeding ticket, how can innocence or guilt be proved either way?

sevenhills said:

Grumpy_chap said:

I am actually with the OP on this one.  If the gantry signage reads 40 mph and there is no signage to revert back to NSL, then the limit remains 40 mph.  It is possible that the OP missed the NSL sign, or just that gantry was out for some reason.  There comes a point where you have to take a judgement call that you did miss the NSL sign and then speed up but I doubt that would stand up in court.

I don't get how any gantry or temporary speed limit is enforceable, unless there is a photo of the vehicle speeding and the sign.

If I get a speeding ticket, how can innocence or guilt be proved either way?

If there’s a photo, it will show both your car and the sign. 

Otherwise, an officer’s statement is valid evidence. Whether it’s “proof” is a decision for the court.

How does it do that when they're on the same gantry as the limit signs?