Friday, 4 March 2011

Two-and-a-half bikes to every motor vehicle: Blackfriars and why this bridge needs space for cycling

A shot from a single traffic light sequence on Blackfriars Bridge this morning, heading north over the bridge and into the gyratory system.

It is exactly on this point where the camera is sited that TfL is planning to add a third lane so that motor vehicles can travel faster through this junction, making it significantly more dangerous for both cyclists and pedestrians. And yet, as this shot shows, in one single traffic light green phase there are 2.5x as many people on bicycles as motor vehicles.

I think this video very usefully demonstrates why this gyratory scheme shouldn't take people for granted just because they're on bicycles.

You might also notice just how narrow even the existing bike lane is at this point and how some of the motor vehicles clip into the bike lane and every one of them that isn't in the far lane strays incredibly close to the bicycle area. Surely time to widen the facility for bicycles here?


  1. When it gets warmer I suppose these numbers can increase. I wonder how does it relate do Boris' cycle revolution? I remember him saying that if there were more cyclists, then Superhighways would be separate from traffic. Well - we have more cyclists then cars on the bridges - is it time for him to keep his word?

  2. In the past week I've started occasionally using Blackfriars bridge northbound on my commute. The cycle lane for most of the bridge is good, except towards the end approaching the traffic lights, where it narrows by about a metre, just at the most dangerous point of interaction with vehicles. Sigh.

  3. TfL's defence of their scheme states that hte cycle lane will remain at the "minimum" 1.5 metre width. THat minimum might be defensible on a straight stretch of road but this stretch has a marked curvature. It takes little understanding of elementary geometry to see that a straight line must either cut a chord on a circle, or lay a tangent to it. When a long vehicle such as a bus or artic lorry takes that curve they have the alternative of eithe rcutting the chord and going into the right hand lane, and likely hitting another motor vehicle - much damage, or laying a tangent and infringing the cycle lane, possibly hitting a cyclist. But of course the blood wipes off quite easily!

  4. Something else to point out with the new plan is that motor traffic from Queen Victoria Street heading south onto Blackfriars Bridge are effectively travelling round a large radius bend that encourages speed and may cut across the path of cyclists on their inside. At this point the road widens to three lanes and yet the cycle lane ends. This seems similar to the old configuration northbound before the protected section of cycle lane around the left hand bend was built.

  5. Hmmm, given the clear figures showing cycling as a serious growth area, shouldn't any new road layouts/resurfacing/linepainting lead to an increase in cycle/bus space? Short wide stretches of road, leading into narrow stretches just causes bunching and queue jumping, in effect reducing the flow as everyone jostles for position, instead of going forward... .