What's the purpose of advisory cycle lanes?

Pete Owens
Posts: 2442
Joined: 7 Jul 2008, 12:52am

Re: What's the purpose of advisory cycle lanes?

Post by Pete Owens »

Greg wrote:
Richard Mann wrote:Advisory cycle lanes across side roads reduce accidents by reminding drivers of the potential presence of cyclists.

Do you have any stats for that?

What the research actually shows is that cycle lanes cause an increase to accidents at side roads. This is particularly severe in the case of mandatory lanes which have to be discontinued across the junction.

So it is not the case that advisory lanes improve safety at junctions - it is just that they are less of a hazard than discontinuous mandatory ones.
Pete Owens
Posts: 2442
Joined: 7 Jul 2008, 12:52am

Re: What's the purpose of advisory cycle lanes?

Post by Pete Owens »

Richard Mann wrote:Advisory cycle lanes across side roads reduce accidents by reminding drivers of the potential presence of cyclists.
Advisory cycle lanes between side roads give a sense of security (largely unfounded) to nervous cyclists,
which encourages them to cycle more. It probably leads to motorists passing marginally closer, but there doesn't appear to be much safety impact of that.

The most common complaint of nervous cyclists is that motor traffic passes too close.
Any feature (such as a pinch point or cycle lane) that causes traffic to pass closer than otherwise will discourage those nervous cyclists.

Now it is true that many people believe that cyclists will be encouraged by cycle lanes, but that is because they mistakenly believe that cycle lanes cause motor vehicles to give cyclists a greater clearance when tho opposite is in fact the case (apart from those rare cases of cycle lanes meeting the 2m standard).
Advisory cycle lanes can be used to mark cycle lanes alongside parking.

One of the first things a cycle trainer will teach novice cyclists is DO NOT RIDE IN THE DOOR ZONE.
This is a concept that most 10 year olds seem to be able to understand but seemingly beyond the grasp of adult traffic engineers.

Put a cycle lane near to parked cars and ...
Novice cyclists will put themselves at risk by riding in the lane.
Competent cyclists who understand the need to position themselves outside the lane will suffer agression from motorists.
There should be a (min) 0.5m buffer zone between the parking bay and the cycle lane.

Car doors swing open well over 1m - any buffer zone needs to be at least 1.5m if a cycle lane is going to allow cyclists to adopt a safe road position.
Of course they should be accompanied by appropriate parking control.

of course they very rarely are in practice.
The main virtue of advisory lanes is that the signs regs are much less prescriptive. If you actually follow the signs regs, you need a veritable forest of signs for mandatory lanes.

That is not a virtue of advisory lanes but yet another fault of mandatory lanes.

Yes advisory cycle lanes are much less bad than mandatory lanes, but that does not mean they are a good idea.

- and actually the main advantage of advisory over mandatory lanes is that since traffic is permitted to encroach an advisory lane there is no need to maintain a full width general traffic lane. This means there is never an excuse to install advisory lanes that are narrower than the 2m road space that cyclists need.
Greg
Posts: 162
Joined: 9 Feb 2007, 8:39pm

Re: What's the purpose of advisory cycle lanes?

Post by Greg »

Pete Owens wrote:
Greg wrote:
Richard Mann wrote:Advisory cycle lanes across side roads reduce accidents by reminding drivers of the potential presence of cyclists.

Do you have any stats for that?

What the research actually shows is that cycle lanes cause an increase to accidents at side roads. This is particularly severe in the case of mandatory lanes which have to be discontinued across the junction.


I really would like a reference for that, please. I have a Shibboleth login, so pay-walls are no problem.
Richard Mann
Posts: 427
Joined: 21 Nov 2009, 12:46am

Re: What's the purpose of advisory cycle lanes?

Post by Richard Mann »

See http://www.cyclox.org/what-we-say/dual-network/safety-of-cycle-lanes/ for details of the studies.

Cycle lanes have worked for us in Oxford. Feel free to advise of somewhere in the UK where an alternative approach has worked better.

Richard
Pete Owens
Posts: 2442
Joined: 7 Jul 2008, 12:52am

Re: What's the purpose of advisory cycle lanes?

Post by Pete Owens »

What does Cyclox have against cyclists - is it a front organisation for Clarkson?
They appear to be actively campaigning to make conditions worse for cyclists and undermine the need for standards.

I can understand a naive campaign group that was unaware of how cycle lanes realocate road space away from cyclists to motor vehicles would be in favour of cycle lanes - but even then I would have thought any organisation would prefer cycle lanes to wide rather than narrow.

But this seems to actively promote poor quality yes it says we have seen the evidence that cycle lanes increase the danger at junctions. But rather than remove the cause of the problem (ie the cycle lane) they suggest a continuation across the junction than probably does make the situation lees bad. However, they notice that the problem still persists (see the last paragraph on Botely Road), but again, rather than remove the cause of the problem (ie the cycle lane) they splash on the red paint.

When they see the evidence that narrow cycle lanes increase danger to those using them they point out that the more statistically significant effect is to moped riders - as if cyclists are somehow less vulnerable (maybe they think the fact we have to propel ourselves makes us tougher). When they see the evidence that cycle lanes mean that drivers give us less space they say bring it on - we can take it (perhaps they prefer their trucks within slapping distance).

When they note that 50cm is not wide enough for accomodate an opening car door they advocate channeling cyclists into the danger zone and suggest that cyclists dodge round them - a tad tricky when your room for manouevre is restricted by a cycle lane.

While cycle lanes have been springing up all over the country over the last 15 years, it is perhaps unsurprising that few are implemented to such consistently poor standards as in Oxford.
Pete Owens
Posts: 2442
Joined: 7 Jul 2008, 12:52am

Re: What's the purpose of advisory cycle lanes?

Post by Pete Owens »

Greg wrote:
Pete Owens wrote:What the research actually shows is that cycle lanes cause an increase to accidents at side roads. This is particularly severe in the case of mandatory lanes which have to be discontinued across the junction.


I really would like a reference for that, please. I have a Shibboleth login, so pay-walls are no problem.


Take a look at John Franklin's Cycle list of research:
http://www.cyclecraft.co.uk/digest/research.html

I think the relevant paper is:
"Safety benefits of cycle lanes
Coates. Velo City, Graz, 1999.
Study of Oxford, UK, where 25km of cycle lanes have been introduced in last 20 years. Some accident savings along cycle lanes away from junction, mainly due to reduction in traffic speed as a result of the lanes taking space from motor traffic. At junctions, cycle lanes can increase accidents, especially if the lanes are not carried through the junction. Main benefits lie in reducing perceived risk, and assisting cyclists to pass other traffic in congested urban centres.
"

This is the one referred to in Cycle Friendly Infrastructure when they advocate cycle lanes continue across side roads.
Note the interesting title for a paper that actually discovers that cycle lanes increase risk.

This is a fairly common pattern in cycle facility research. Authors seem to approach their research committed to the idea that segregation is a good idea and seem surprised to discover increased risk. Rather than conclude that perhaps the cycle lane/path or whatever they are studying is a bad idea they tend to downplay their own results and try to find other positive things to say - for example they point to "percieved risk" - or a small gain in safety under one specific set of circumstances will be emphasised even if it is overwhelmed by the general increase in risk - or the recommend an adjustment to the design that may make things less bad and promote this as a safety feature.
irc
Posts: 5192
Joined: 3 Dec 2008, 2:22pm
Location: glasgow

Re: What's the purpose of advisory cycle lanes?

Post by irc »

thirdcrank wrote:As others have mentioned, riding outside a cycle lane can cause unnecessary grief from drivers (it's still something I for one can do without even if I know I'm in the right.) A few years ago now, I was 'disciplined' by a lorry driver for not riding behind a white which was actually an 'edge of carriageway' marking. It's not much help knowing you are in the right in those circumstances.


Been there.

doorzonecyclelane.jpg


I've had a few instances of drivers overtaking extremely close to punish me for not using this "facility". Further on it is no better. It's a parking lane all day outside a gym. At least here drivers can see why I'm not using it. Even if the cars weren't in it there is a poor surface full of the usual grit, broken glass etc.

gymcyclelane (Large).jpg
No one believes more firmly than Comrade Napoleon that all animals are equal. He would be only too happy to let you make your decisions for yourselves. But sometimes you might make the wrong decisions, comrades, and then where should we be?
Richard Mann
Posts: 427
Joined: 21 Nov 2009, 12:46am

Re: What's the purpose of advisory cycle lanes?

Post by Richard Mann »

Pete Owens wrote:I think the relevant paper is:
"Safety benefits of cycle lanes
Coates. Velo City, Graz, 1999.
"

A pdf of this paper is on the cyclox website: http://www.cyclox.org/wp-content/upload ... Coates.pdf

Pete Owens wrote:This is a fairly common pattern in cycle facility research. Authors seem to approach their research committed to the idea that segregation is a good idea and seem surprised to discover increased risk.


All research has bias, some in favour of cycle lanes, some rabidly opposed. The stats basically say that if you take certain precautions then the safety impact is small (probably a small benefit overall, but it's not statistically significant). So you can implement them (or not) on comfort grounds.

In Oxford the politics is supportive of there being cycle lanes, and we have a lot of cyclists. You are welcome to try an alternative approach, and I'd be more than interested to hear of your success. But if you insist on repeating that Oxford's narrow cycle lanes are a death trap then I will insist on repeating that the fatality rate of narrow cycle lanes has been grossly exaggerated.

{By the way, mopeds are different from bikes because they go faster. That makes a noticeable difference both to the reaction time available, and to the effect of hitting a car door. Which I thought would be obvious.}

Richard
Richard Mann
Posts: 427
Joined: 21 Nov 2009, 12:46am

Re: What's the purpose of advisory cycle lanes?

Post by Richard Mann »

irc wrote:
doorzonecyclelane.jpg


Could you advise approx traffic flow and speed (and preferably the widths of the cycle, traffic and turning lanes).

From the volume of traffic (nil), it would not be appropriate to have a cycle lane on the road. There's no point having cycle lanes when there's less than about 5000mvpd (ie cars normally have to deal with an oncoming vehicle when passing a cyclist). It also looks like the traffic might typically be doing more than 30mph, in which case a wider cycle lane (and/or buffer zone) would be required. But it's hard to tell from a static photo.

Richard
irc
Posts: 5192
Joined: 3 Dec 2008, 2:22pm
Location: glasgow

Re: What's the purpose of advisory cycle lanes?

Post by irc »

Richard Mann wrote:
irc wrote:
doorzonecyclelane.jpg


Could you advise approx traffic flow and speed (and preferably the widths of the cycle, traffic and turning lanes).

From the volume of traffic (nil), it would not be appropriate to have a cycle lane on the road. There's no point having cycle lanes when there's less than about 5000mvpd (ie cars normally have to deal with an oncoming vehicle when passing a cyclist). It also looks like the traffic might typically be doing more than 30mph, in which case a wider cycle lane (and/or buffer zone) would be required. But it's hard to tell from a static photo.

Richard


The picture is deceptive. I maybe took it going to work at 6AM or some other quiet time of day. Traffic flows will be circa 20'000 vehicles a day. It's a main arterial route. As for widths. I don't have the exact widths. What I can say is that the right turn lane is narrower than a vehicle width. If their is a right turning car waiting in the right turn lane it's LH tyres are still in the main traffic lane. Following traffic uses the cycle lane to undertake it because otherwise they are having to pass within inches.

I have complained to the council but they don't see a problem. Apparently cyclists were consulted at the planning stage.

Luckily my commute was outside peak hours. In peak hours most cyclists stay in the doorzone lane as getting out in to the main lane requires fairly positive, even aggressive, cycling. Traffic speeds are typically 30-40mph. Closer to 30 at peak hours. It is a 30mph limit..
No one believes more firmly than Comrade Napoleon that all animals are equal. He would be only too happy to let you make your decisions for yourselves. But sometimes you might make the wrong decisions, comrades, and then where should we be?
cjchambers
Posts: 855
Joined: 29 Jun 2008, 9:55pm
Location: Hartlepool

Re: What's the purpose of advisory cycle lanes?

Post by cjchambers »

Cyclox Website wrote:The consensus appears to be that a “critical reaction strip” of at least 50cm is required alongside the parking. This isn’t enough room for a car door to open, but it appears to be enough room for the cyclist to dodge round if a door opens in front of them.

WHAT!? Dodge?! Dodge around an opening door?! Into the stream of motor traffic?! I'm lost for words!
Richard Mann
Posts: 427
Joined: 21 Nov 2009, 12:46am

Re: What's the purpose of advisory cycle lanes?

Post by Richard Mann »

irc wrote:Traffic speeds are typically 30-40mph. Closer to 30 at peak hours. It is a 30mph limit..


If traffic speeds are over 30mph, then the cycle lane+buffer zone needs to be wide enough for car doors to open fully. You can't expect cyclists to dodge out into the traffic when the speed differential is that high. You can only get away with the sort of narrow dimensions that we've used in Oxford if traffic speeds are kept down. A buffer zone of 1m (ie a parking bay of 2.8m), a cycle lane of 1m and no turning lane is probably the answer. Alternatively, you can force speeds down by putting in a continuous turning lane / median strip, traffic islands and a speed camera.

Richard
cjchambers
Posts: 855
Joined: 29 Jun 2008, 9:55pm
Location: Hartlepool

Re: What's the purpose of advisory cycle lanes?

Post by cjchambers »

Richard Mann wrote:You can't expect cyclists to dodge out into the traffic when the speed differential is that high.

You can't expect cyclists to dodge out into traffic at all - no matter what the speeds are. If the swerving cyclist is about to be overtaken by a large van or lorry, 'dodging' would mean instant death even at 20mph. This does happen - door zone deaths do happen. Door zone cycle lane deaths do happen.

Image
(This is just one example - http://www.bikexprt.com/massfacil/cambr ... laird1.htm)

What this picture is telling us is . . . . stay out of the door zone. Staying out of the door zone is one of the simplest ways to avoid becoming a sad statistic. There's genuine debate to be had about the potential benefits of on- and off-road facilities, but I'm frankly horrified that a cycle campaigning group is campaigning in favour of narrow door-zone cycle lanes.
irc
Posts: 5192
Joined: 3 Dec 2008, 2:22pm
Location: glasgow

Re: What's the purpose of advisory cycle lanes?

Post by irc »

Richard Mann wrote:
irc wrote:Traffic speeds are typically 30-40mph. Closer to 30 at peak hours. It is a 30mph limit..


If traffic speeds are over 30mph, then the cycle lane+buffer zone needs to be wide enough for car doors to open fully. You can't expect cyclists to dodge out into the traffic when the speed differential is that high. You can only get away with the sort of narrow dimensions that we've used in Oxford if traffic speeds are kept down. A buffer zone of 1m (ie a parking bay of 2.8m), a cycle lane of 1m and no turning lane is probably the answer. Alternatively, you can force speeds down by putting in a continuous turning lane / median strip, traffic islands and a speed camera.

Richard


i think I'd prefer the recommended (for busy roads) 2m wide lane with 0.5m - 1m buffer zone. As per paragraphes 7.4.2 and 7.5.2 of the link below.

http://www.dft.gov.uk/pgr/roads/tpm/ltnotes/ltn208.pdf

Anything less and I'd prefer the lane not to be there at all. I agree there are other options but the council don't see there is any problem.
No one believes more firmly than Comrade Napoleon that all animals are equal. He would be only too happy to let you make your decisions for yourselves. But sometimes you might make the wrong decisions, comrades, and then where should we be?
Richard Mann
Posts: 427
Joined: 21 Nov 2009, 12:46am

Re: What's the purpose of advisory cycle lanes?

Post by Richard Mann »

irc wrote:i think I'd prefer the recommended (for busy roads) 2m wide lane with 0.5m - 1m buffer zone. As per paragraphes 7.4.2 and 7.5.2 of the link below.

http://www.dft.gov.uk/pgr/roads/tpm/ltnotes/ltn208.pdf

Anything less and I'd prefer the lane not to be there at all. I agree there are other options but the council don't see there is any problem.


I think you'll find the hierarchy of solutions says you should do traffic or speed reduction before you put in cycle lanes. Once you've done speed reduction, then you don't need wide cycle lanes. Arguably you don't "need" cycle lanes at all, but I think you'll have fewer cyclists if you get rid of them.

Get the council to do a speed survey on the road. They shouldn't be tolerating regular speeding over a 30mph limit.

Richard
Post Reply