Catching the GREEN Light

Background Reading


The test site alongside the busy city ring road of Utrecht.

The test site alongside the busy city ring road of Utrecht.


Maybe it is time to try some 21st Century technology rather than relying on outmoded approaches like the Idaho Stop Law to keep cyclists moving. The article begins:

We’ve all experienced it: you arrive at a red traffic light and the moment you come to a full standstill the light changes to green. Or you see that the light is green in the distance and you think it will turn red again before you get there, but it only does a second before you do. In those cases it would have made sense to slow down or to speed up just a little bit and the stop could have been avoided. If only you had known the light would change when it did! With your personal Light Companion you could have adjusted your speed and you would indeed not have had to stop. The longer ahead you would have had information about the upcoming green time, the easier it would have been to adjust your speed and stopping could become a thing of the past.

The Light Companion is a development by Springlab, an innovation agency in Utrecht. Jan-Paul de Beer, director, explained to me that their system was inspired by an installation in Copenhagen, but it goes further. “We studied the Copenhagen system and we all liked it, but we also thought that it could be improved by making it more personal. Their LED lights in the surface go on and off whether there are people cycling or not. Our system will give personalised information, that is a big and important difference.”

The Light Companion is a LED-light tube that can change colour. It was 75 metre long in this test installation. At the beginning you are detected when you cycle past and a green light, the length of your bicycle, appears. If you follow the speed of that light it will guide you personally through the green traffic signal ahead. The speed of the light is calculated on the basis of the green time in the cycles of the traffic light installation. But that you are detected 75 metres ahead of the traffic light also influences that green time cycle. Most Dutch traffic light installations work with detection loops for all road users. Motor traffic is detected as well as pedestrians and of course people cycling. There are guaranteed green phases in the total green cycle of 90 seconds. A road user has a right to a fixed green time when such a road user is present. When one of the arms of the intersection or one of the cycleways is clear of traffic, other road users get the time that becomes available to use for them, so early detection helps getting a bit more green time. The traffic light installation at this intersection was explained to me in great detail. Also by pointing at all the information shown on the real-time monitor. There are so many detection points at that intersection that you can actually see road users showing up and leaving again when the lights change. When we then looked up to the real junction we would also see those people and the vehicles in reality. It was nice to see people arriving on their bicycle getting a green light more than 10 seconds before their scheduled green time, because they were detected by this new system 75 metres before they arrived at the intersection. The light was also green for much longer when there were several people detected. The light stayed green until the last person crossed the final detection loop.