Wednesday 16 June 2010

Bus Lane Trial Should End Now

Boris' scheme to put motorbikes into bus lanes was always ill-conceived. Today's data from the first trial period shows its downright dangerous for many road users. He should swallow his pride and scrap the extension of the trial now before more people get hurt unnecessarily.

Remember this? At the time Boris's rather grumpy remarks were ascribed to the fact that he'd been held up by protesters in Trafalgar Square. With hindsight might there have been an additional cause for his displeasure? Namely that bikers behaviour in bus lanes had come perilously close to scuppering one of the few manifesto promises he's managed to keep. As it is TfL have had to 'fess up today that putting powered two-wheelers into bus lanes has increased accidents by a considerable margin. You'd think that ought to be enough to have the trial scrapped. Not a bit of it. No-one outdoes the current Mayor on stubbornness and he's not about to change his ways now. Through TfL Boris announced an extension of the trial claiming:
...the initial trial has shown some positive results

From the data presented, I fail to see what these could possibly be. There are two main areas for concern. TfL commissioned detailed research from the Transport Research Laboratory (TRL) to determine if safety, amongst other things, had been affected by the change. This report compared sites where motorbikes were allowed in bus lanes with areas where they were not. The results for motorbike safety are pretty clear. For cyclists the conclusions leave something to be desired in my view.

Firstly, collisions of motorcycles with other road users have increased. The report produced concludes clearly that there is statistically significant increase in collisions involving motorbikes where they have been allowed access to bus lanes compared to where they have not been.

Secondly, collisions involving cyclists have also increased (again by a statistically significant margin) in those bus lanes where motorbikes have been allowed. Unfortunately, however here the report gets a bit hazy. It suggests that an analysis of the particular mode of collisions indicates that the presence of motorbikes is not the cause of the increase, and that an increase in cycle flow will "partially" explain the increase. There are a number of problems with this analysis as far as I can see. The report itself identifies that this analysis depends on a subjective assessment by a traffic officer of the cause of a particular collision. You have therefore introduced opinion into your (up-to-now) strictly factual analysis of collision data. It also relies on the the traffic officer giving the cyclist a fair-go. I would not impune the professionalism of our police in London, but I am not sure they always understand the difficulties that cyclists have navigating the city.
Perhaps more substantially the report presents no firm conclusion as to why the accident rate did increase beyond a partial explanation. To my mind that should indicate that you know there's an increase but you don't know why. Consider this for example, the reports suggests most collisions involving cyclist were as a results of poor observation (i.e. I didn't see the bike, car etc.). Is it possible that a general increase in traffic in bus lanes with bikes zipping past you at 30MPH has made situational awareness a more difficult task for cyclists. Intuitively, as a cyclist myself I think it has. Has it made it more likely I will have an accident with something other than a motorbike? I have no way of knowing and importantly neither do the authors of the report. The assertion therefore that the increase is not connected with the presence of motorbikes is flawed in my view. There's either a real impact on cyclists from motorbikes by a mechanism that has not been considered, or alternatively there's a significant confounding variable that makes comparisons between the test and control sites unreliable generally.

Either of these changes in road safety should have meant the trial wasn't extended. Why? Well imagine if Boris' had introduced the initial trial run as follows:

I am going to allow motorbikes into bus lanes. I am aware that this will impact their safety and will produce more road accidents and injuries. In addition there will be more collisions involving cyclists, some of whom will also be injured. I will pretend I understand why, by some mechanism not fully explained, collisions with cyclists increase and insist it is nothing to do with the motorbikes. In reality I will be clueless.

Gentlemen, please start your engines!

Sadly that is exactly what he effectively said to us today. It would have been nice for him to be interviewed perhaps on why he thinks the extension is a good idea. Sadly he doesn't seem to be around:

@mayoroflondon: By the spectator zone at the Cape Town Waterfront http://twitpic.com/1x95yi

Nice life isn't it?

4 comments:

  1. The extension was put in place because a lot of the evidence was inconclusive. Biker deaths are down considerably - proportionately to the number of bikers on the road.
    Bikers are also victims of the 'I didn't see him'/'he appeared out of nowhere'/'i didn't bother looking' excuses - and as a biker myself, i have felt much safer in bus lanes since the scheme began.
    There have been occasions where someone turning left doesn't look where they are going, but that is up to the biker to ensure that they are able to react.
    The same goes for cyclists.
    We all have to get by on the road - and everyone must do their part.
    It seems to me like the cycle lobby don't want to do theirs.
    They have been opposed consistently, regardless of evidence, to the scheme - and it seems to me like BoJo is just not listening to either lobby while he gathers more data.
    I hate to say it, but thats a good idea - not making up your mind before the conclusion is drawn by experts?

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  2. I couldn't agree more that we need to base these decisions on evidence. It is why I am somewhat perplexed by a number of aspects of your comment.

    Firstly on a factual basis I can see no evidence from the trial of a reduction in casualties. You might be right that biker deaths may be down generally on London's roads, I don't know whether that's true or not. But there is no evidence from the trial that opening bus lanes has influenced that at all. So it would be misleading to say the least to try and confuse a general trend with the specific effect of allowing access to bus lanes.

    You say you feel safer. That may be your perception but unfortunately the evidence says that's categorically wrong. Ironically as well as putting cyclists at danger, the trial has increased your risk level as well.

    More generally it might have been credible before the results of this trial to say that people were making a decision without evidence. Not any more. I have to take issue with your statement that the evidence is still inconclusive - it isn't. The trial has increased risks to both cyclists and motorcyclists and that's clear and unambiguous from the monitoring. The only question remaining I can see is where the extra risk to cyclists comes from. That's not quantity we should be testing on the roads and the only reasons we are continuing is because of a political imperative on the Mayor's part.

    The cycle lobby has been concerned precisely about the effects that the evidence indicates have come about. That there would be more casualties amongst cyclists and they have been proved right. If you could demonstrate some tangible safety benefit for motorcyclists (beyond perception) you might have a case to say that the trade-off is appropriate. That isn't there - by continuing this trial everyone loses.

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  3. One thing I don't understand is either cyclists or motorcyclists who ride without mirrors. As a motorcyclist and driver in London I am constantly scanning my mirrors to keep up with traffic movement around me, and can't understand how anyone can use the roads safely in London if they are unaware of what's going on around them. As for those cyclists I see wearing earphones or talking on mobiles........

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  4. Colin:

    On headphones I have to admit I went through a phase early on of doing this myself. I have stopped now and you're right it is wrong. Ditto on mobiles although I've never even attempted that. You do see people doing it but I'm not sure how you could ever have a conversation on a bike.

    Mirrors are interesting - I don't have them and most cyclists don't. They (and me) rely on good all-round observation but maybe its time to re-consider that.

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