Corner Speed signs
Discussion
koenig999 said:
On the M5 today, a corner was signed as a 50 mph limit, and everybody was going round at 70 +
What is the legal standing of these signs / limits?
Koenig
Unless speed limit is in red circle, the speed is only advisory.
I am fed up with numpties that slow down when they see these signs and refuse to go faster and not get out of my way.
Agreed with whats already been said. Only one I've ever seen that is actually necessary is for a very sharp bend on the A303 (I think). Signed as max. speed 20 or 25mph. 35-40 is just about safe (you can see around the corner) but without the sign it would be easy to misjudge the corner.
I know it's childish but I am sure that I am not the only one that sees these patronising 'there's a bend you need to slow down' signs as a challenge. They just seem to be goading you in to finding out what the actual 'maximum speed' is. Probably not the safety effect they were going for.
rustybin said:
I know it's childish but I am sure that I am not the only one that sees these patronising 'there's a bend you need to slow down' signs as a challenge. They just seem to be goading you in to finding out what the actual 'maximum speed' is. Probably not the safety effect they were going for.
Yes indeed - but for 2 things.
Some of them are probably not far off the mark and some genuine limits (round sign) are quite realistic. For example the 40 limit on the southbound J24a exit on the M1 can be quite tricky especially in the wet. And it is a very long curve so can catch people out.
Secondly - think well loaded artic with a high C of G or a load which might be subject to some movement even though constrained.
But in a car, particularly one with sporting characteristics, on an otherwise clear road ... I agree with most previous comments.
devils advocate=on
M5 J4 sharp bend sign and advisory 50 limit.
OK so 70 is quite possible, but don't you think it might be there for a reason?
Like to raise awareness that there is, in motorway terms, a bend sharper than normal, that just around the bend is an on-slip with very restricted visibility all round.
Of course by all means blat round at 70 and upwards to that totally safe 100+ we keep hearing about, and then what do you do when you've failed to consider the on-slip. Don't give me crap about the joining traffic should give way, yes they should. They may have made their observations and decisions about joining before you were in sight at your "oh so safe speed the advisory limit doesn't apply to me, I'm a good driver I am."
So who are the numpties now?
devils advocate mode = off.
M5 J4 sharp bend sign and advisory 50 limit.
OK so 70 is quite possible, but don't you think it might be there for a reason?
Like to raise awareness that there is, in motorway terms, a bend sharper than normal, that just around the bend is an on-slip with very restricted visibility all round.
Of course by all means blat round at 70 and upwards to that totally safe 100+ we keep hearing about, and then what do you do when you've failed to consider the on-slip. Don't give me crap about the joining traffic should give way, yes they should. They may have made their observations and decisions about joining before you were in sight at your "oh so safe speed the advisory limit doesn't apply to me, I'm a good driver I am."
So who are the numpties now?
devils advocate mode = off.
Anyone entered the M6 northbound from I think its the A500 Stoke?
20mph signed, and boy do they mean it!
Theres another 50mph limit, as you're coming clockwise around the M60 before you get to Stockport, signed 50mph, but I expect thats because visibility is actually quite poor, and traffic often queues around those parts.
Personally I quite enjoy coming off the M6 northbound onto the M62 eastbound - very tight left hander that does a 270 degree turn....
20mph signed, and boy do they mean it!
Theres another 50mph limit, as you're coming clockwise around the M60 before you get to Stockport, signed 50mph, but I expect thats because visibility is actually quite poor, and traffic often queues around those parts.
Personally I quite enjoy coming off the M6 northbound onto the M62 eastbound - very tight left hander that does a 270 degree turn....
parrot of doom said:
Anyone entered the M6 northbound from I think its the A500 Stoke?
20mph signed, and boy do they mean it!
Oh yes! One of the best.
And then hardly any acceleration lane and the northbound M6 traffic unable to see how things are developing.
Nice bit of road planning.
LongQ said:
Anyone entered the M6 northbound from I think its the A500 Stoke?
20mph signed, and boy do they mean it!
Oh yes! One of the best.
And then hardly any acceleration lane and the northbound M6 traffic unable to see how things are developing.
Nice bit of road planning.
That's J15 - and like quite a lot of the sliproads with these reduced speed signs, there's very little visibility so, even if you could take it a higher speed you'd be a lot of trouble if traffic had stopped around the bend.
That entry can also get very slippy, I presume from tyres laying rubber down as they scrub, and trucks dropping oil in one concentrated place. I've experienced this on other slip roads too, and the surfaces can get pretty chewed up.
towman said:
How it was explained to me by Trafpol Crash Investigator.....This is the speed to travel around the corner if you don`t want granny on the back seat to feel uncomfortable.
The original work dates back more years than I care to mention (It was done by RRL, which was the precursor to TRRL which is now TRL, that bane of all right-minded speeders), but it basically assumes a lateral acceleration (cornering 'g') of around 0.2-0.22g (varies with the radius of turn), and was linked to passenger comfort in the days when cars had bench seats, no seatbelts and more body roll that you could shake a stick at. I seem to remember standing bus passenger acceleration limits appearing somewhere in all that as well.
Given that acceleration is proportional to speed squared and your car will generally have a steady-state (i.e. what they can achieve in a constant radius turn) of around 0.7-0.9g, then in theory you could go round at roughly double the posted speed. And no, I wouldn't necessarily recommend attempting it, either.
The speeds quoted tend to match the speed at which Yorkie man in his laden wagon will generally be approaching the point of rollover.
StressedDave said:
How it was explained to me by Trafpol Crash Investigator.....This is the speed to travel around the corner if you don`t want granny on the back seat to feel uncomfortable.
The original work dates back more years than I care to mention (It was done by RRL, which was the precursor to TRRL which is now TRL, that bane of all right-minded speeders), but it basically assumes a lateral acceleration (cornering 'g') of around 0.2-0.22g (varies with the radius of turn), and was linked to passenger comfort in the days when cars had bench seats, no seatbelts and more body roll that you could shake a stick at. I seem to remember standing bus passenger acceleration limits appearing somewhere in all that as well.
Given that acceleration is proportional to speed squared and your car will generally have a steady-state (i.e. what they can achieve in a constant radius turn) of around 0.7-0.9g, then in theory you could go round at roughly double the posted speed. And no, I wouldn't necessarily recommend attempting it, either.
The speeds quoted tend to match the speed at which Yorkie man in his laden wagon will generally be approaching the point of rollover.
I still think smoothness has a lot to do with this. Even if you take bends fairly briskly, the discomfort that could be caused to a passenger is minimised by easing the lock on and off gently, and sweeping through the bends with a bit of finesse. This is especially relevant when there's a bit of snow on the deck like last night. Even when it's slippery you can get along quite well if you read the road properly.
Best wishes all,
Dave.
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