Monday, 29 September 2008
Default to green
Stopping on a bike and restarting again has a similar effect on the cyclist to travelling hundreds of extra metres, so regularly stopping for junctions makes cycling less viable as a means of transport.
One of the many joys of cycling in this country is that the cycle paths allow you to make progress without stopping too often. There are many ways that this is arranged, including having the paths away from the roads and taking different routes. For instance, on most of our cycle journeys from home here we don't meet any traffic lights at all. I can cycle to the centre of the city seeing no traffic lights while driving there I would encounter a minimum of two sets. I can cycle to my dentist and meet one set of traffic lights, or drive there and go through five sets.
The video shows another example. At this traffic light junction the lights default to green for bikes and only switch directions to allow motorised vehicles to pass on the road if they drive up to the detector and wait for a while. They get a maximum of six seconds or so and then it's back to green for cyclists again. It's like a button controlled pedestrian or cyclist crossing, but in reverse. As you'll see in the video, I could cycle through this without stopping. I usually can.
There are other clever things done with traffic lights here, such as having a simultaneous green phase for bikes to go in all directions at once, which again increases the average speed of cyclists.
There are many other examples of traffic light junctions, things which make cycling more direct, and the intercity cycling superhighways for long distance commuters on this blog. This cycle path is part of my commuting route, and part of the reason why I commute so much quicker now than I used to.
This crossing will feature in the 2009 Study Tour.
A few years ago in the UK I measured the average time for a green for a motorist or pedestrian at a crossing near where we lived and found that while motorists had an average delay of under 8 s and a maximum of 30 s, pedestrians had an average delay of 38 s and a maximum of a minute. There are also crossings at which cyclists using a shared use path have to stop and press more than one button to cross a single road. Cambridge recently installed a junction with four button presses being required to cross a single road.