M4 South Wales Newport / Cardiff - why 50 ?!?
Discussion
Afternoon
Title says it all really.
Visiting the land of song for the rugby.
Cross bridge, pay to enter!!, meet roadworks , 50 mph enforced by Avg speed camera no problem with that . Exit roadworks perfectly clear, functional M4 with zero roadworks 3 lanes all clear BUT very permanent looking 50 mph repeaters in central reservation with SPECS to enforce and all the Matrix and yellow signs to remind you....WTF?!?......then some miles later (all at a mind knumbing 50mph) get near cardiff & Enter more roadworks.. 50 mph enforced by Avg speed camera no problem with that..
Fully understand and agree withthe 50mph in both sets of roadworks (these are M25-esque is size!)... but why hold everybody at 50 between them??. Looking at us all chugging along at HGV speeds it started getting very close and congested as the normal car/lorry speed differential doesn't exit... at at 50 everybody seems to think i'm 'only' at 50 so can close right up !
Any one from S Wales police got an idea!?!
thanks
Title says it all really.
Visiting the land of song for the rugby.
Cross bridge, pay to enter!!, meet roadworks , 50 mph enforced by Avg speed camera no problem with that . Exit roadworks perfectly clear, functional M4 with zero roadworks 3 lanes all clear BUT very permanent looking 50 mph repeaters in central reservation with SPECS to enforce and all the Matrix and yellow signs to remind you....WTF?!?......then some miles later (all at a mind knumbing 50mph) get near cardiff & Enter more roadworks.. 50 mph enforced by Avg speed camera no problem with that..
Fully understand and agree withthe 50mph in both sets of roadworks (these are M25-esque is size!)... but why hold everybody at 50 between them??. Looking at us all chugging along at HGV speeds it started getting very close and congested as the normal car/lorry speed differential doesn't exit... at at 50 everybody seems to think i'm 'only' at 50 so can close right up !
Any one from S Wales police got an idea!?!
thanks
jonesy100 said:
Afternoon
Title says it all really.
Visiting the land of song for the rugby.
Cross bridge, pay to enter!!, meet roadworks , 50 mph enforced by Avg speed camera no problem with that . Exit roadworks perfectly clear, functional M4 with zero roadworks 3 lanes all clear BUT very permanent looking 50 mph repeaters in central reservation with SPECS to enforce and all the Matrix and yellow signs to remind you....WTF?!?......then some miles later (all at a mind knumbing 50mph) get near cardiff & Enter more roadworks.. 50 mph enforced by Avg speed camera no problem with that..
Fully understand and agree withthe 50mph in both sets of roadworks (these are M25-esque is size!)... but why hold everybody at 50 between them??. Looking at us all chugging along at HGV speeds it started getting very close and congested as the normal car/lorry speed differential doesn't exit... at at 50 everybody seems to think i'm 'only' at 50 so can close right up !
Any one from S Wales police got an idea!?!
thanks
Presumably set up as a revenue earner. Absolutely no reason to be 50mph IMHO.Title says it all really.
Visiting the land of song for the rugby.
Cross bridge, pay to enter!!, meet roadworks , 50 mph enforced by Avg speed camera no problem with that . Exit roadworks perfectly clear, functional M4 with zero roadworks 3 lanes all clear BUT very permanent looking 50 mph repeaters in central reservation with SPECS to enforce and all the Matrix and yellow signs to remind you....WTF?!?......then some miles later (all at a mind knumbing 50mph) get near cardiff & Enter more roadworks.. 50 mph enforced by Avg speed camera no problem with that..
Fully understand and agree withthe 50mph in both sets of roadworks (these are M25-esque is size!)... but why hold everybody at 50 between them??. Looking at us all chugging along at HGV speeds it started getting very close and congested as the normal car/lorry speed differential doesn't exit... at at 50 everybody seems to think i'm 'only' at 50 so can close right up !
Any one from S Wales police got an idea!?!
thanks
According to the signs the limit is there for 'Safety Reasons'.
Can't work that one out - I've driven that stretch of road for donkey's years, mainly at 70mph and never killed myself or anyone else or even come close to having an accident.
Come to think of it I can't recall even seeing an accident there. Of course I could just have been lucky and missed the carnage that MUST occur there regularly.
Not sure if the limit is enforcable - perhaps some experts could advice. I always thought that repeaters needed to be illuminated if there was no street lighting. Last time I passed along there the street lighting was turned off and the signs weren't illuminated.
BB
Can't work that one out - I've driven that stretch of road for donkey's years, mainly at 70mph and never killed myself or anyone else or even come close to having an accident.
Come to think of it I can't recall even seeing an accident there. Of course I could just have been lucky and missed the carnage that MUST occur there regularly.
Not sure if the limit is enforcable - perhaps some experts could advice. I always thought that repeaters needed to be illuminated if there was no street lighting. Last time I passed along there the street lighting was turned off and the signs weren't illuminated.
BB
How wide are the lanes?
There was once a short section of the M62 (now M60) between the end of the M602 and the M61 that was 50 limit for a while due to the lanes being below a certain width, (or so I was told), and that permission had to be granted for the limit to be raised to 70. After about 6 months the limit went back up. The lanes were narrow because the road had been "widened" from 3 lanes to 4. IIRC that section of the M4 has been widened from 2 to 3 lanes, so maybe the circumstances are the same.
Or I could be talking rubbish?
There was once a short section of the M62 (now M60) between the end of the M602 and the M61 that was 50 limit for a while due to the lanes being below a certain width, (or so I was told), and that permission had to be granted for the limit to be raised to 70. After about 6 months the limit went back up. The lanes were narrow because the road had been "widened" from 3 lanes to 4. IIRC that section of the M4 has been widened from 2 to 3 lanes, so maybe the circumstances are the same.
Or I could be talking rubbish?
EU_Foreigner said:
This madness being the current government I assume? 
Not this time, or not Whitehall anyway. This one is down to the Gas and Air factory in Cardiff (Welsh Assembly)
Also see this thread on the South Wales forum
http://www.pistonheads.com/gassing/topic.asp?h=0&a... 50 limit through Newport
Edited by rs1952 on Monday 9th November 17:35
"A high-tech system that changes speed limits in response to road conditions is to be introduced on a stretch of the M4 in south Wales"
Well, at least all of us who use the M25 won't be alone now in our frustrations at how crud the system is.
Perfectly flowing traffic activates the lower limit signs..
Traffic starts to bunch up as a result...
Signs activate to suggest there is now a queue ahead (due to the bunching up)
Traffic bunches up even more..
Even lower speed limit signs light up..
Traffic bunches/crawls/stops.
Not sure about anyone else, but I have driven under such signs just as they have activated and have been on the phone to people ahead of me who have seen them enabled and they are as mysterious as the fog warning signs which flash during cloudless summer days.People have no idea why they are lit and why they stay lit for so bloody long after any "event".This evening on the M25 they were down to 40 mph for a few hundred yards, then back to national speed limit signs.As per usual, many ignored them, some slowed to 40, others anchored up to 40 mph only to see the 70 mph sings a few gantries ahead, so darted about and floored it again.As per usual, I have no idea why.It caused the usual chaos though.It's amazing really, you can lap the M25 and only come across problems, with startling regularity in fact, when you reach those damn signs.Coincidence?
Out of what must now be hundreds of times of seeing various signs, I have only seen one incident which made me understand why they were enabled.Just one! They cause most of the queues imho and all this 'debris in road' stuff, well, I prey for the day I actually see some.More often than not, even if there were debris, it will have been cleared away and probably sold on ebay before the signs go off.Incredible.
Well, at least all of us who use the M25 won't be alone now in our frustrations at how crud the system is.
Perfectly flowing traffic activates the lower limit signs..
Traffic starts to bunch up as a result...
Signs activate to suggest there is now a queue ahead (due to the bunching up)
Traffic bunches up even more..
Even lower speed limit signs light up..
Traffic bunches/crawls/stops.
Not sure about anyone else, but I have driven under such signs just as they have activated and have been on the phone to people ahead of me who have seen them enabled and they are as mysterious as the fog warning signs which flash during cloudless summer days.People have no idea why they are lit and why they stay lit for so bloody long after any "event".This evening on the M25 they were down to 40 mph for a few hundred yards, then back to national speed limit signs.As per usual, many ignored them, some slowed to 40, others anchored up to 40 mph only to see the 70 mph sings a few gantries ahead, so darted about and floored it again.As per usual, I have no idea why.It caused the usual chaos though.It's amazing really, you can lap the M25 and only come across problems, with startling regularity in fact, when you reach those damn signs.Coincidence?
Out of what must now be hundreds of times of seeing various signs, I have only seen one incident which made me understand why they were enabled.Just one! They cause most of the queues imho and all this 'debris in road' stuff, well, I prey for the day I actually see some.More often than not, even if there were debris, it will have been cleared away and probably sold on ebay before the signs go off.Incredible.
Digby said:
It's amazing really, you can lap the M25 and only come across problems, with startling regularity in fact, when you reach those damn signs.Coincidence?
I don't think it is coincidence either. I still can't get my head around how slowing people down could increase journey times or how natural weight of traffic isn't a more effective variable speed limiter. Of course, someone's making money out of selling these systems which is far more attractive than just spending the money to engineer out problem areas in the road network. But that couldn't possibly influence decisions.cornishjon said:
They've had a couple of accidents recently involving lorries along that stretch - at least one of them fatal - both occassions resulted in the motorway being closed for a good few hours causing carnage.
I think it's a response to that.
TOTAL pain in the @rse !!!
I live just off the stretch in question (the bendy bits around Newport). There were a handful of very serious accidents within the space of a few months that involved lorries breaching the central reservation barriers and hitting oncoming traffic. Each accident caused absolute chaos because the geography of the region means there's no alternative roads that follow the same route as the M4 - you either end up in the centre of Newport (trust me, nobody wants to end up in the centre of Newport) or heading due north up a valley towards Brecon. They're in the process of replacing all of the central barriers along that stretch with high concrete ones. Once that's done, apparently there'll be a variable speed limit system set up. I think it's a response to that.
TOTAL pain in the @rse !!!
As long as they remember to switch the limits back to NSL outside of rush hour, I'm all for it. The traffic on the M4 around here in rush hour (and when there's an event on in Cardiff) can be absolutely horrendous.
cornishjon said:
They've had a couple of accidents recently involving lorries along that stretch - at least one of them fatal - both occassions resulted in the motorway being closed for a good few hours causing carnage.
I think it's a response to that.
So in response to accidents involving vehicles limited to ~56mph, they limit everyone else to around the same speed, mixing you in with the lorries. I'd put money on the number of sideswipes from people on the limit, hovering alongside in the blind spot, increasing. I think it's a response to that.

Perhaps it's just to pay for the beefed up central barriers?


GHW said:
As long as they remember to switch the limits back to NSL outside of rush hour, I'm all for it. The traffic on the M4 around here in rush hour (and when there's an event on in Cardiff) can be absolutely horrendous.
One of my pet hates is the way they try to micro manage the traffic. If a cow farts they think its high wind and lower the limits to 50. They leave the signs on well past rush hour, I assume Trisha or some other day time rubbish is on is on and they are hooked. I would like to know what guidance that gas and air shop in Cardiff will or have given them.I commute through this stretch every day and yes, when the road's empty it's a pain in the arris to be held to 50 mph. But...
Since this 50 mph enforced limit came in everyone drives at or around 50 mph which means that there's no stop-start traffic caused by reps trying to do 90 in the fast lane and diving across at the last minute for their exit. Because we're all doing the same speed, they tend to get in the right lane in plenty of time so all the panic-braking caused by these heroes has gone and my journey time has REDUCED by ten minutes each way. Fuel economy has improved by 5mpg too, for obvious reasons.
Out of busy times it makes no sense at all but in the rush hour it works a treat.
Since this 50 mph enforced limit came in everyone drives at or around 50 mph which means that there's no stop-start traffic caused by reps trying to do 90 in the fast lane and diving across at the last minute for their exit. Because we're all doing the same speed, they tend to get in the right lane in plenty of time so all the panic-braking caused by these heroes has gone and my journey time has REDUCED by ten minutes each way. Fuel economy has improved by 5mpg too, for obvious reasons.
Out of busy times it makes no sense at all but in the rush hour it works a treat.
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