Monday 10 November 2008

Traffic Lights

On the North side of the Vaart in Assen is a bicycle road which has no traffic lights on it all the way into the centre of the city. That's the primary route in this direction.

Today we're on the Southern side of the same canal, on a secondary cycling route, which has this one set of traffic lights for cyclists.

There are a number of interesting things here.

The parallelogram features on the ground are the second set of detectors for bicycles which you roll over on the way to this light. The first set is about 50 metres before the lights. It is advantageous to cyclists to have their own detectors as they are never set up so that they only detect cars. Having the double set means that often the lights have changed for you before you reach them.

There is also a yellow button on a post which allows a cyclist to make sure that the traffic light controller is aware of their presence. If the detectors should fail, then this gives another way of indicating the presence of a cyclist.

Next we have the green sign on the traffic light post, which indicates this is a simultaneous green junction at which cyclists can go in any direction they want (left, right, straight on, diagonal) when there is a green light. All motorised traffic is at a standstill while this happens.

The same junction as at the top of this post, from the road on
the right in the top photo, before the approach was
improved for bikes
Cyclists are never given a green to cycle straight on while drivers have a green to turn right. To do this would put cyclists into the most dangerous and lethal position on the road. This is why we do not have junctions designed in the same way as in Denmark.

Also note that you can see lamps on the lampposts ahead over the cycle path as well as over the road. This helps to improve the social safety of this cycle path at night.

Finally, note the width of the cycle path. It's over 3 metres in width, even though it's merely a secondary route paralleled by the 5 metre wide bicycle road on the other side of the canal.

This is proper cycling infrastructure which attracts cyclists, designed for a high degree of actual and subjective safety. It is part of what has resulted in Assen having 41% of all journeys by bicycle - a higher cycle modal share than can be claimed anywhere outside the Netherlands.


Anonymous said...

Wow detactors! Is this like the inroad detactors to make the light change? It is so aggravating here to come to an intersection and not be able to get the light to change because you are on a bicycle.

David Hembrow said...

Yes, they're coils under the tarmac. You can see two of them in the photo, the odd shapes that look like they're cut out of the tarmac. There is another set a few metres behind the camera to catch bikes as they approach.

Because these are passed only by bicycles, they are very reliable for bikes. However, there is still the button as well as the two sets of detectors just to make sure.

Usually these lights go green as I roll up to them. Not bad, but generally I'll have had to slow down, which makes them not quite as good as the ones which default to green for bikes.

Kevin Love said...

In Toronto, there are three white dots on the road to indicate where the bicycle detection device is is placed. Stopping a bicycle over the three dots will signal the traffic light to change.

As far as I know, only Toronto uses the three white dots method. Further details at:

Adrienne said...

I wonder how this could be made to work in a city with an impacted and established road system. I can see the bike friendly light system, but I don't know how roads like that could be built here. A struggle, to be sure.

David Hembrow said...

Adrienne, how old is the place you're thinking of ? Assen has existed for 750 years. It's been a city for 200 years.

I don't know the age of this particular road, but there are buildings a little way past the camera position which display dates from early in the 20th century.

Nevertheless, this road was completely renewed last year (I took a photo of the works in progress).

The age of existing infrastructure is not in itself a barrier to improvement.

Adrienne said...

I am thinking of the older parts of San Francisco, specifically. Many of the older neighborhoods are quite narrow with on street parking on both sides of the street. There would be no place to put this kind of system, unless the parking was taken out (SF currently only has 2/3 of the needed spaces to accommodate the number of people who drive into the city, so no one is going to go for less parking). Even then, in many of these places, you would also have to significantly narrow sidewalks.

At what point do we start talking about creating subjective safety through education of drivers and cyclists? I do not fear cars or traffic, although I am very aware of them. I was taught to ride predictably and to communicate constantly with other vehicles (it helps that I am also a motorcyclist, so I am accustomed to keeping my car awareness very high). In doing this, I have very few uncomfortable incidents, even in heavy traffic. When I do, I find the problem usually lies in me thinking people can read my mind and get out of my way.
In my daily riding, I see poor bicycle habits and badly trained car drivers as more of an issue than infrastructure (clueless pedestrians cause ooooodles of trouble around here, too).

David Hembrow said...


As you know, San Francisco is a much newer city than most European cities. I understand that not much of it is older than 1906, when the fire and earthquake destroyed much of the city.

It's possible to change streets, however old they are. A recently published book shows some of what Assen has done in the last 30 years.

You can also read a previous post which compares a street here in Assen with one of the same width in Cambridge (where I used to live).

If you want everyone to cycle, then cycling has to be made into a very easy thing to do. A very attractive thing to do. Irresistible, even. You need high subjective safety.

It doesn't come from telling people to put themselves in the way of motor vehicles. You may have a high tolerance of the danger posed by motor vehicles, but other people do not.

Being fearful of cars is not irrational. They've killed as many people in the last century as wars have, and they continue to be the main cause of death and injury of cyclists even here.

Keeping cyclists away from cars is however a very effective way of reducing the number of collisions, including fatal collisions. It gives safety in a passive way, rather than expecting perfect behaviour from all road users at all times. It also increases the safety both of those who are trained cyclists and those who are not. What's more, it gives an opportunity to give cyclists better routes than drivers. More direct routes, with more pleasant surroundings and with fewer stops for traffic lights.

The average citizen of this city makes more than 1.1 cycle journeys per day. It is doubtful that this would be the case if cyclists were expected to mix with motorised traffic. Rather this would increase the uncertainty that people would feel about cycling, putting some off, and it would increase cycle journey times leading to cycling losing at least some of its speed advantage.

You would expect to see the early signs of cycle unfriendly infrastructure first. Children no longer being allowed to cycle alone, no longer being allowed to play on the streets, old people no longer cycling etc.

Cyclists are a bit like pit canaries. You can see how healthy your cycle culture is by looking at who they are, how they behave and how they look.