Road surfacing causes crashes
Safety fears over surface material of fastest roads
Many crashes could be caused by a roads surfacing material that's being misused, according to police crash investigators. They're worried because in certain conditions, stone mastic asphalt (SMA) offers little grip for two years until bedded in. And SMA is the blacktop often used for motorways and main roads in the UK -- yet it's been banned in Ireland because of safety concerns.
On BBC Radio's File on 4, police sergeant Jim Allen reported how in 2001 he tested some newly laid SMA on a warm sunny August day, in the course of investigating the cause of a crash. He said, "I jumped on the brakes and the car just kept going and going. Instead of the screaming of tyre on road and a cloud of smoke, there was just a gentle hiss and I skidded far further than I ever expected to."
He said that he was very surprised and concluded that the grip level was low. Investigating further and examining the tyres of his car, Allen found that the heat generated by the tyres as they braked had melted the bitumen so that, instead of gripping stones, the car was floating on molten bitumen.
File on 4 highlighted how resistance tests are often carried out in the wet and on worn surfaces but not in dry conditions, which is just when SMA's critics say slipperiness occurs on new, dry roads.
One local council carried out tests and admitted there were problems. Yet an industry body said that it didn't test for skid resistance on new roads because it assumed older roads would cause the problem.
Eire has now banned SMA from roads whose speed limit is above 30mph, and has resurfaced SMA-laid faster roads. Germany, the pioneer of SMA use in the 1960s, has also seen concerns about grip, as has the Netherlands.
The UK's Highways Agency said that British SMA in Britain has a different consistency, and that the materials have been thoroughly inspected. And File on 4 reported that SMA is the only surface that is approved for unrestricted use on the UK's roads of all types.
The AA Motoring Trust warns the road network is in its worst condition since the 70s and said: "Surfaces are a hidden menace. In London as many as a third of main roads need looking at. There could be lives at risk."
The Government says it is spending more than £31 billion over 10 years on highway repairs.
They're complaining about incorrect materials, what about all the other roads around the country where the road surface is so bad that your likely to loose control under heavy braking etc due to undulations changes in grip from different materials used in road repairs.
Just another excuse isn't it.
tvrman said:
I did hear the program on Radio 4 and it was very interesting. On another note a while back Autocar did testing in the rain, with the more expensive road surfaces, there as much less spray.
At the end of the day it's going to come down to money, more than safety.
Ian
I don't think there is much difference in price or durability between the free draining tarmac and non draining tarmac - It's just government policy to use the rubbish stuff
>> Edited by Ruxpin on Monday 28th February 12:00
off we don't care and no we won't be changing regardless of the safety issues.The favourite beyond the pale (outside Dublin) is a good old spray of tar and enough chippings to ensure everyone driving on that road for the next 3 years will need a bonnet respray and a new windscreen. If anyone's planning a driving holiday in Ireland, leave the Tiv behind and hire a landrover!!!
According to recent data a person is 147 times more likely to die if they are struck by a car doing 34mph rather than 30mph.
If the friction levels of road surfaces are known to be poor then the limits should be reduced still further to compensate for the longer braking distances. Did you know that a person is 122 times less likely if struck by a car doing 25mph rather than 30.
If it just saves one life it will be worth it.
HOWEVER, anything has better grip than pot holes worn surfaces, cracked surfaces, loose gravel etc. If you want to see a bad main road, view the main road from Broadford to Portree. It breaks the buses on their regular route.
I live in the Kirklees area and 99% of every road is a joke if you dont have a 4 x4 then don't vist, if a hole appears in the road they fill it in with a speed hump.
The main motorway's runing past are the M62 and M1 and it dont matter what material you lay on them its just one large car park anyway soon you will have to leave your car to go get a ticket to stick on your window.
Tazfan said:
So, they are saying they are spending £31 Billion over 10 years eh? At the current levels, how much ROAD Tax are we collectively paying a year? I bet £31 Billion over 10 years is only a small fraction of the revenue ROAD Tax generates. I wonder why they dont spend ALL the ROAD Tax on the roads for which we pay to drive on.
Yep, by latest figures that's about 6 months worth of motoring taxes!!!
kevinday said:
What's the betting this will become the latest excuse for the high number of road deaths? Or is used as a 'reason' for lowering speed limits for 'safety'?
Well if Ireland banded why did we not, it is always the cheap option it seems, the so-called experts over should take a look at themselves.
it would be intresting is someone manages to sue the local council for an acciedent they had because of the type of road surface?
have just read the report and it stated that it had only been tested on car tyres what happens when you have 44 ton artic???
Surely by now they should know which road surface is quiet and whats not, and whats safe and whats not, or this yet another case of YES IT IS ROCKET SCIENCE.
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