Your personal guide to catch the green light

Cycling is best when you don’t have to stop. Stopping itself is not so hard, but to get going again, that takes a lot of extra power. So people prefer to stop as few times as possible when they are cycling. No wonder traffic lights were mentioned as the biggest frustration in cycling when that was asked in Utrecht last year. To do something about that frustration Springlab in Utrecht is trying to develop the Light Companion. And it is going well. After a year of preparations, including a test last Summer in a controlled environment, it was now time for a test in a real life traffic situation. The test took place on Tuesday, 3rd of November 2015.

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

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.”

Everything that happened was monitored real-time at different locations.
Everything that happened was monitored real-time at different locations.

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.

Monitoring the intersection. All the pale blue squares indicate detected road users and all the lights indicate different states of the lights. More than just red, yellow and green there were also colours for 'waiting for green' and various other states.
Monitoring the intersection. All the pale blue squares indicate detected road users and all the light dots indicate different states of the different lights. More than just red, yellow and green there were also colours for ‘waiting for green’ and various other states. Clearly visible in this map is the fact that this is a protected intersection like most bigger intersections in The Netherlands. The actual test took place on the cycleway at the bottom right hand side.

It would be even better if the green cycle would be adjusted even further when there are people approaching on a bicycle. At the moment there still is an arrival time possible that will lead to a stop no matter how fast or slow you ride. Eliminating that stop is a political choice. Jan-Paul de Beer feels that this project is also good to fuel the political debate about these choices. “Suppose this all works in future and this system is implemented everywhere, then it means that when the green light runs that the bicycle traffic light really has to turn green in time. Priority has to be given to the cyclist. I notice that you can trigger politicians with something like this to start thinking about that.”

The Utrecht politicians have already started to think about this. The bicycle is given precedence in the mobility policy of the municipality of Utrecht, meaning that people cycling have been determined to be the number one road user. The Utrecht alderman for traffic and the environment, Lot van Hooijdonk already acts accordingly (the constant improvement of cycling infrastructure, earlier corrections of traffic light installations and innovations such as the Bicycle Parking Guidance System are a testament to that). She is also crystal clear in my video, when she says that because of this policy no measure taken to improve cycling is too much.

The Light Companion banner was already in English. You never know if you can market this abroad too!
The Light Companion banner was already in English. You never know if you can market this abroad too!

“The way we construct intersections is really on our radar lately” she tells the gathered people who came to witness the official opening of this experiment. “Utrecht is growing and we try to let the growth happen within the boundaries of the current city. That means it gets busier. It is a challenge for the traffic light guys – unfortunately they still are mostly men – to guide all road users safely through the intersection in a time that also makes them a bit happy, at least happy enough to keep obeying these lights. We support this project for the promise it offers us. I can see an image glimmering at the horizon, where I see groups of people cycling in a relaxed way, because they know when the lights will change. When other road users are also grouped, it would make it easier to design the intersections. You can then try to align the gaps between the groups in such a way, that they cross each other much easier than today, maybe even in shorter times, with more happy road users.”

My video report of the test of the Light Companion.
A big thank you to both people I interviewed
for willing to speak English for your convenience!

This one day test was a step in the direction of this vision of the future. People were asked what they felt about this system and (apart from the unsurprising muttering about costs) the response was largely positive, but there was also room for concern. Saskia Kluit, the new director of the Dutch Cyclists’ Union, told an RTL news reporter “In busy places an incredible lot of things happen at the same time. You have to pay attention to other people cycling and to signs and lights, if you then also have to watch a light on the ground I wouldn’t be surprised if you miss it.”

The test continued well into the night, showing that it was much easier to see the green guide in the dark.
The test continued well into the night. This video shows that it was much easier to see the green guide in the dark. Tweet by Springlab.

The developers will continue to work with all the comments and the test results they received. “We will now try to make an installation that can be tested for at least one month,” says Jan-Paul de Beer on the website of the Utrecht municipality after the test, “only then you can really see if it improves the bicycle traffic throughput and if it makes an intersection safer. That will require an installation that can withstand the weather conditions and that won’t be easily damaged”.

Lot van Hooijdonk agrees: “We will have to continue after this test, to find out if it really is safe, if it can be built solid enough, if it is affordable. So we are not there yet, but it gets me really excited. I see this as a promise to the future that I hope we can fulfil together.”

If all goes well the first ‘Light Companion’ could be implemented on the route to the Utrecht Science Park, next year.

16 thoughts on “Your personal guide to catch the green light

  1. Very cool idea! I think it could be a great help to heavy rush-hour cycling through a long sequence of traffic lights.

    Someone already posted the link to Clotilde Imbert’s explanation of the Copenhagen Green Wave.

    Here is another video. This one made in 2007 in Odense. 45 bollards are timed to 15 km/hr.

    The feasibility is there.

  2. What range of speeds are the lights designed to go? And is the existing speed of the cyclist taken into account with that?

    1. The installation identified two types of cyclists, fast and slow. If I remember correctly the difference over the 75 metre distance was 5 seconds. The traffic light expert tried to explain everything to me but I didn’t get this point about how that works technically. So there are two stages for these types of cyclists, but I don’t know how the installation can identify either one.

  3. I am not entirely certain what pedestrian lights mean. I see them being green and red and flashing green but the flash is too short for an elderly person to cross the road, and probably even to reach the central median. What is the meaning? And how are they detected (also I would like to know whether traffic lights are able to add signal stages when a light is already green)?

    I also would like to know what your opinions Mark and others are about bicycle traffic lights that have the capability of using the simultaneous green if more than one directions have a bicycle detected but no cars from anywhere detected. It would mean that all directions of bicycles, and if present pedestrians, get green at the same time, because there are no cars to wait for.

    1. If you are referring to the video at 0:43, then first of all, this only shows the very end of the green light phase for pedestrians and cyclists. My feeling is that pedestrians in The Netherlands get a decent amount of time to cross, at least compared to the UK, say. The flashing green light means that you’re not allowed to start crossing anymore (i.e. like amber). Pedestrians are not detected, but have to press a button, although e.g. here they are automatically included with the cyclists green phase.

    2. The flashing green is not a separate ‘walk’ phase, but the end part of the green phase. So it is indeed too short for a slow walker to cross, but that is no issue. It means ‘You still have green, but start evacuating the crossing’. A faster pedestrian can cross increasing his or her pace; a slower pedestrian can wait for the next green phase, which will have amply time to cross.

    3. I find this a very confusing traffic light phase in the Netherlands. I think flashing green man means that you can still legally start crossing, but the red man will appear in 3 seconds. I have no idea if the clearance period starts with the flashing green man or the red man though.

      1. That is right, you may still cross when the light flashes green, but you don’t have to. It is a warning that the red light will appear soon. The first few seconds of the red time is the actual clearance period (at least with a pedestrian light).

    4. The green is analogous to the North American white man (or the word “Walk” on older signals). The flashing green is analogous to the North American flashing orange hand gesturing “stop” accompanied by the number of seconds left until you may not cross anymore (or the flashing “Don’t Walk” on older signals). The red is analogous to the North American steady orange hand (without a countdown) (steady “Don’t Walk” on older signals).

      1. The flashing green man in NL is different to the North American flashing hand in that flashing green means you may still start to cross, but the light is about to go red, whereas the flashing hand means do not start to cross.

        The flashing green man is fixed at about 3 seconds regardless of the width of the road, because (as I understand it) the pedestrian clearance period is actually during the red man phase, so the flashing green man is nothing more than a warning that it will soon become illegal to start crossing. I’ve never come across a system where flashing green man means it is still safe to start crossing anywhere else in the world.

        On the other hand, the North American flashing hand is the clearance period and therefore its duration depends on the width of the road. There is no equivalent of the Dutch flashing green man in North America.

  4. Having also read the blogpost about this at, it sounds like an interesting experiment, but I have to agree with Hilary Staples in that I find it doubtful whether this will bring real benefits.

    I think that having a countdown timer (both for when the light turns green and red! I’ve only seen timers showing the time for it to turn green) and advanced dectection loops goes a long way to reaching the same effect and seems simpler and less costly to me.

    Then again, the only way to find out whether this has advantages is by trying it out…

    1. Interesting, I hadn’t seen Hilary’s post yet. She seems to think the light cycles are not affected by this system, but I was told they are (and it was visible on the monitor). By the advanced detection loops, exactly as you would also like to see. I do agree that this may seem complicated, but we will only know when the system is combined for several lights to see if it is indeed leading you through them smoothly. Probably the best thing though is getting rid of the lights altogether. That is what ‘s-Hertogenbosch has done on the main cycle route. That truly leads to non-stop cycling.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.