Cycling On Dual Carriageways

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Pross
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Cycling On Dual Carriageways

Postby Pross » Wed Jul 03, 2013 10:09 am

OK, following on from the thread regarding the sad news of the two cyclists killed on the A30 I thought I'd start a new thread to discuss this. As I have said on that thread I don't believe a road is necessarily unsafe just because it is a dual carriageway with a national speed limit. I believe there is far more to it than that such as the length of visibility available, width of the road, volume of traffic, number and type of junctions and conditions at a particular time. I cited two sections of the A40 in South Wales as an example of how things can differ. The first is a section between Abergavenny and Raglan that is regularly used for time trials, it is continuous with no junctions has very wide lanes, fairly low traffic flows and excellent visibility when dry (being concrete the spray is terrible in the rain). In the 20 odd years I've been riding there must have been well in excess of 250,000 cycling miles done racing on that section and I am unaware of any serious accidents involving cyclists (and very few involving vehicles). Accident statistics show that there have been a few slight injury accidents involving cyclists in the last 10 years but I haven't been able to get the details so they may or may not have involved collisions with vehicles. The second section is the A40 from Raglan to Monmouth (and the adjoining section of A449 to Usk) which is also used on several TT courses. Here the lanes appear narrower as does the hard strip, there are slip road junctions, traffic volumes are higher and the visibility is more restricted in places. There have been fatalities on this section in TTs.

I think it is too easy to just say high speed dual carriageway = dangerous, there are plenty of heavily trafficked sections of single carriageway road where people will drive 50 - 60 mph (or higher) and on encountering a cyclist will not have the width to pass due to oncoming vehicles.

Smidsy made the following comments in the other thread:-

Yes speed is not specifically an accident waiting to happen, but the fact is that if you are on a fast road on something that can only do 20mph the speed differential is the real problem. Also drivers on such wide/open roads are not expecting such a difference and by the time they realise the problem it is often too late.

The reason the HA make people get out of their stranded vehicles now is because 'statistically' you will be hit within 8 minutes of stopping on the hard shoulder. Something that in your profession you should also know only too well.

Regardless of the statistics of accidents there really is no place for cycling on fast dual carriageways.


To take those points on board:-

1. Yes, the speed differential is a key issue but if you are on a road with a mile of visibility then it should provide anyone driving with anything approaching the expected level of care and attention to easily gauge the discrepancy and adapt their driving accordingly. It is far more likely that someone will encounter a cyclist 'unexpectedly' whilst driving at 50mph on a winding country A road leaving them with no chance to react. A differential of 35mph with 2 or 3 seconds to react to and no space to take action it is worse than a differential of 60mph with 30 seconds to react and the space to take action.

2. I have no idea where that '8 minute rule' comes from, I would like to see a link to the research as the only reference I can find is on motoring forums. Bearing in mind most cars that end up on a hard shoulder are there for substantially longer than 8 minutes then the chances of getting hit would be far greater than not getting hit and fatality rates of breakdown patrol people would be massive.

3. Given the choice I wouldn't cycle on a high speed dual carriageway but to generalise and say they are all 'unsafe' isn't particularly helpful or true.

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Re: Cycling On Dual Carriageways

Postby keef66 » Wed Jul 03, 2013 10:22 am

I regularly see TT's happening on the A11 where the traffic volumes are high and the standard of driving low. I've witnessed a couple of near misses on long slip-roads where the merging motorist has been looking over his shoulder for vehicles coming up behind him, and completely failed to notice a cyclist in front. I wouldn't cycle on the A11 any more

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Peat
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Re: Cycling On Dual Carriageways

Postby Peat » Wed Jul 03, 2013 10:24 am

I have heard the '8 minute rule' bandied around before, although i thought it was more 14mins. Something to do with target fixation.

In the other thread, i brought up speed-differential. Thinking about it, it's the same for just about any road. However, a driver's attitude on Dualy's is very different. They often drive very fast and close, regardless of conditions and the last thing they anticipate would be someone on a bicycle. It shouldn't be that way, but it is.

Also, lorries often drive very close to one another (from what i've seen). I am picturing a situation of a 2 tailgating lorries, Lorry A & B. The traffic in lane 2 is heavy (it's 8:30am on a weekday afterall), Lorry A see's cyclists up ahead and looks for a gap. Fortunately for him, one opens up just in time that he doesn't need to get out of the gas to complete the maneuver. Lorry B is unsighted and is suddenly confronted with 2x cyclists a lorry length away, doing >30mph less. If you add in that the driver was looking in his mirror/adjusting lights or radio etc, there is no time to react.

I'm not saying that is what happened. But it's a plausible situation.

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Ballysmate
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Re: Cycling On Dual Carriageways

Postby Ballysmate » Wed Jul 03, 2013 10:34 am

Fast traffic, particularly lorries, passing closely can have the effect of sucking you in and spitting you out again. And watch out for those crosswinds! :shock:

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drlodge
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Re: Cycling On Dual Carriageways

Postby drlodge » Wed Jul 03, 2013 10:38 am

A main factor has to be the ability of a car or lorry to pass the cyclist with another vehicle overtaking them in the outside lane. If the road cannot accomodate a 3 wide formation (cyclist-vehicle-vehicle) then the vehicle coming up behind the cyclist will have to slow from potentially 60-70mph to around 15mph in quite a short distance. And if they leave it too late, something is going to collide.
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Pross
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Re: Cycling On Dual Carriageways

Postby Pross » Wed Jul 03, 2013 10:44 am

Peat wrote:brought up speed-differential. Thinking about it, it's the same for just about any road. However, a driver's attitude on Dualy's is very different. They often drive very fast and close, regardless of conditions and the last thing they anticipate would be someone on a bicycle. It shouldn't be that way, but it is.

Also, lorries often drive very close to one another (from what i've seen). I am picturing a situation of a 2 tailgating lorries, Lorry A & B. The traffic in lane 2 is heavy (it's 8:30am on a weekday afterall), Lorry A see's cyclists up ahead and looks for a gap. Fortunately for him, one opens up just in time that he doesn't need to get out of the gas to complete the maneuver. Lorry B is unsighted and is suddenly confronted with 2x cyclists a lorry length away, doing >30mph less. If you add in that the driver was looking in his mirror/adjusting lights or radio etc, there is no time to react.

I'm not saying that is what happened. But it's a plausible situation.


I'm not disagreeing, my only disagreement is with the assumption that a dual carriageway is less safe as it is a dual carriageway. I would argue that you need to take any road on and individual basis when assessing how 'safe' it is rather than making that assumption based on whether it has a central reservation separating the carriageways or not.

If I was doing any kind of leisure ride I would avoid dual carriageways but that's at least partially down to them being less enjoyable to ride on with the noise and traffic levels. I'd also try to avoid heavily trafficked A or B roads as well.

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adr82
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Re: Cycling On Dual Carriageways

Postby adr82 » Wed Jul 03, 2013 10:51 am

Dual carriageways aren't especially dangerous in themselves, it's just a combination of the usual piss-poor way of dealing with cyclists that many motorists have combined with the higher than normal speeds involved. And as you say the layout of particular roads can make a difference too. However at least on a dual carriageway you will always be very aware of the dangers (as a cyclist)... I think I'd prefer that predictablity compared to being on a quiet country road with the chance that at any given corner some moron might come racing around it at 50mph, happily assuming the road must be completely empty. I've had more near misses like that than I've had on dual carriageways.

drlogdge wrote:A main factor has to be the ability of a car or lorry to pass the cyclist with another vehicle overtaking them in the outside lane. If the road cannot accomodate a 3 wide formation (cyclist-vehicle-vehicle) then the vehicle coming up behind the cyclist will have to slow from potentially 60-70mph to around 15mph in quite a short distance. And if they leave it too late, something is going to collide.

Slow down? Hah, I wish. If they have a choice between slowing down for a few seconds or diving through the gap between the bike and the vehicle on the outside, they will often just dive right through regardless of how close that involves getting to the cyclist. Example: http://www.youtube.com/watch?v=pONptAsmRQc - that was ridiculously close and the road wasn't even busy. Impatience is the cause of so many problems on the roads.

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monkimark
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Re: Cycling On Dual Carriageways

Postby monkimark » Wed Jul 03, 2013 10:55 am

I would always avoid national speed limit dual carriageways where possible for the reason pointed out by Ballysmate above - the idea of a 7.5 tonne truck passing a couple of metres away at 60mph is enough to put me off even contemplating it.
Anything with sliproads on/off would be a major concern too.

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Re: Cycling On Dual Carriageways

Postby hatch87 » Wed Jul 03, 2013 11:08 am

The problem is on long straight roads is its to easy to get distracted and bored as a driver. Thats when people start fiddling with the stereo or day dreaming, then before you know it they've drifted over the white line. That includes me
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smidsy
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Re: Cycling On Dual Carriageways

Postby smidsy » Wed Jul 03, 2013 11:13 am

Pross wrote:2. I have no idea where that '8 minute rule' comes from, I would like to see a link to the research as the only reference I can find is on motoring forums. Bearing in mind most cars that end up on a hard shoulder are there for substantially longer than 8 minutes then the chances of getting hit would be far greater than not getting hit and fatality rates of breakdown patrol people would be massive.


The numbers change with every study, but that was the point, 'statistically' counts for nothing.

IMO cyling on high speed dual carriageways is not sensible.
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Re: Cycling On Dual Carriageways

Postby RiderUk » Wed Jul 03, 2013 11:15 am

Whilst driving behind a lorry on the M20 recently ,the lorry veered over by at least 3 feet into the hard shoulder on several occasions.Luckily there wasn’t any parked cars on the hard shoulder at the time.
Then I noticed what seemed to be the outer packaging of a cigarette packet being discarded from the driver’s side window.
Presumably the driver had opened a packet of cigarettes, resulting in the loss of concentration whilst driving.
If this had taken place on a dual carriageway, being that there’s only a couple of feet between the lane line and the verge this could have been a different story.
Any road can be dangerous, whether it be an A road or county lane.
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drlodge
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Re: Cycling On Dual Carriageways

Postby drlodge » Wed Jul 03, 2013 11:20 am

adr82 wrote:Slow down? Hah, I wish. If they have a choice between slowing down for a few seconds or diving through the gap between the bike and the vehicle on the outside, they will often just dive right through regardless of how close that involves getting to the cyclist. Example: http://www.youtube.com/watch?v=pONptAsmRQc - that was ridiculously close and the road wasn't even busy. Impatience is the cause of so many problems on the roads.


You brought out the point I was hiding...they'll just barge straight through and not give a flying f**k for the cyclist.
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Pross
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Re: Cycling On Dual Carriageways

Postby Pross » Wed Jul 03, 2013 11:21 am

smidsy wrote:
Pross wrote:2. I have no idea where that '8 minute rule' comes from, I would like to see a link to the research as the only reference I can find is on motoring forums. Bearing in mind most cars that end up on a hard shoulder are there for substantially longer than 8 minutes then the chances of getting hit would be far greater than not getting hit and fatality rates of breakdown patrol people would be massive.


The numbers change with every study, but that was the point, 'statistically' counts for nothing.

IMO cyling on high speed dual carriageways is not sensible.


That's probably because it has nothing to do with statistics, it's just a random number plucked out of the air to try to scare motorists into getting up the embankment and away from their vehicle if they break down. Properly obtained and collated statistics count for far more although if something has a statistical chance of 1:1000000 of killing you and you are the unlucky 1 person then they aren't much help.

IMO riding a bike on a road isn't particularly sensible but we all do it. However, as I've said I wouldn't choose a DC if there was a practicable alternative.

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GiantMike
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Re: Cycling On Dual Carriageways

Postby GiantMike » Wed Jul 03, 2013 11:34 am

I don't and wouldn't. I don't do TTing because a lot of them are on what I consider to be dangerous roads.
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CiB
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Re: Cycling On Dual Carriageways

Postby CiB » Wed Jul 03, 2013 11:43 am

RiderUk wrote:Whilst driving behind a lorry on the M20 recently ,the lorry veered over by at least 3 feet into the hard shoulder on several occasions.Luckily there wasn’t any parked cars on the hard shoulder at the time.
Then I noticed what seemed to be the outer packaging of a cigarette packet being discarded from the driver’s side window.
Presumably the driver had opened a packet of cigarettes, resulting in the loss of concentration whilst driving.
If this had taken place on a dual carriageway, being that there’s only a couple of feet between the lane line and the verge this could have been a different story.

That doesn't prove he wasn't paying attention though - it's reasonable that he was looking and could see the road was clear so wasn't too bothered about keeping exactly in lane whilst he faffed about with his fags. Not ideal by a long way but it's not evidence of what's being suggested.

Dual c/ways differ - bits of the A5 are fine but the A43 from Brackley to Towcester isn't a place I'd like to ride on again. Trouble is it only becomes clear how bad a dc is (or not) when you're on it usually.

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Mikey23
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Re: Cycling On Dual Carriageways

Postby Mikey23 » Wed Jul 03, 2013 12:01 pm

I know this stretch of road very well as I used to drive a group of disabled people up and down it from launceston to Truro college three times a week for three years. It is the major route into Cornwall other than the A38 and both are treated like motorways. No more difficult and dangerous than any other dual carriageway but can be extremely hazardous. Prevailing westerlies usually cause strong cross winds and the combined effect of being sucked at up to 80mph must be about as bad as it gets. It can be tough in a van let alone on a bike. Many times ive really had to focus inorder to keep the high sided van on the road. Volume and speed of traffic and weather conditions mean there is hardly a day without some kind of accident and several fatalities. On the other hand I have seen TTs on it on Sunday mornings in benign conditions with hardly a vehicle in sight and plenty of passing room. I've passed jogling cyclists many times and often all you can do is slow down to about 60 and keep wide to protect yourself and passengers. They nearly always ride in the gutter which is about a foot wide, full of crap and the cats eyes are also mounted there. It's a very hilly road and I can't imagine cycling it can be much fun

I rode it for about half a mile once last year and I was terrified... I will never do it again

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natrix
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Re: Cycling On Dual Carriageways

Postby natrix » Wed Jul 03, 2013 12:17 pm

smidsy wrote:The numbers change with every study, but that was the point, 'statistically' counts for nothing.


So which study did you get your 8 minutes from?????

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Peat
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Re: Cycling On Dual Carriageways

Postby Peat » Wed Jul 03, 2013 12:27 pm

Everyone keeps bringing up TT's. TT's do not take place at rush hour on a weekday, they take place at perhaps the quietest (daytime) time of the week. Also, they are signposted 'cycling event in progress' (the ones i have seen anyway) and you see many riders, making the driver aware.

I simply don't see a parallel to TT's and the sad events near Newquay.

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Re: Cycling On Dual Carriageways

Postby Bozman » Wed Jul 03, 2013 12:44 pm

I live near the A50 in Derbyshire and I'd guess that a few of you have done TTs that start near Etwall and then go down the A50. From a local point of view that route is madness, not just for the A50 but the busy roundabouts that they have to go round, I believe that a guy got killed doing a TT last year.

I wouldn't dream of riding down the A50 so why would you run a TT there?

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Re: Cycling On Dual Carriageways

Postby Spinonit » Wed Jul 03, 2013 12:50 pm

In my humble opinion i would say that cycling on a dual carriageway is no more dangerous than any other road,
In the 30years i have been cycling i have had a near miss on almost every type of road going,
lack of concetraion by drivers and cyclist can happen on any road.


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