Keeping as much distance as possible, at least one and a half metres, may be difficult for cyclists waiting at traffic lights. Before the corona era, large numbers of cyclists were able to bunch up close to each other at stop lines. This also enables large numbers of cyclists to cross the intersection within a relatively short green time. This no longer applies if everyone keeps a distance of 1.5 metres. Cyclists will have to line up further apart, and the current method of releasing cyclists will no longer be sufficient. This requires a different method of working. In this article, we present an overview of possible solutions.
More Cyclists Expected
Public transport is currently less attractive as a travel option for commuting, as the risk of infection is greater than when travelling alone in the car or outdoors on a bicycle. There is also less space in buses and trains: a maximum of 40% of the usual capacity can be used in the coming months. With a relaxation of lockdown measures, people will start moving more and more. The number of short-distance journeys will be the first to increase. Bicycles will be an alternative for both public transport and short car journeys. In other words, there will be more cyclists on the road. And for the time being, fewer motorists than usual. This, too, requires a different working method for traffic light control settings.
Customization of Each Intersection is Needed
The design of each intersection controlled by traffic lights is different, and the load on the various road users is also different. There is therefore no general solution. For each intersection, we have to look specifically at how we can best solve the problem on the spot. This can be done by making changes at the parameter level directly on location. In other cases, reprogramming of existing software is needed.
Shorter Red Time for Cyclists
By keeping the red times for bicycle signal groups as short as possible, the number of arrivals during the red time is as low as possible, and as few cyclists as possible need to line up at the stop line.
- Shorter green for (conflicting) car directions. Most Traffic Light Controllers (TLC)are vehicle-dependent. This means that when no more traffic is detected, the direction in question is steered to red. As a result of the reduced number of journeys, it will also be quieter with motorized traffic at most intersections, so that the green times for motorized traffic are already shorter. For busy (conflicting) car directions, the maximum green time can be adjusted downwards if necessary. At peak times this will result in a worsening of the handling of motorized traffic. This is an example of a parameter change.
- Reduced priority for public transport. By prioritising public transport, conflicting directions of the bicycle signal groups are steered to green sooner, or kept green longer. As a result, the red time of the bicycle directions becomes longer. By adjusting public transport priority measures slightly, red times for bicycle signal groups will become shorter. This too is a parameter chang
- Double realisations for bicycle signal groups. By realising bicycle signal groups several times per cycle the red time of the bicycle signal groups can be kept short. However, care should be taken to ensure that the green times of conflicting motorised traffic also remain short. This may lead to a worsening of the handling of motorized traffic. Sometimes this can be adjusted with parameters, but most of the time it is a software change.
- By allowing more bicycle directions in partial conflicts with turning directions of cars, the red times can be shortened. By limiting the number of conflicts of bicycle directions the cyclist has to wait less time for the direction to turn green. Bicycle traffic has priority over turning motorised traffic, allowing cyclists to continue without stopping when green. However, this solution may affect road safety and may also lead to a worsening of the handling of motorized traffic. This is a software change.
- All cyclists green at the same time. If at an intersection, there are many left hand movements for cyclists, it may be a solution to give all cyclists green at the same time. In that case, the left turn can be made across the intersection in one go. Normally a left-turning cyclist uses two signal groups to complete the movement. This means the cyclist has to wait twice for a red light. By giving all cyclists green at the same time, only one wait for red is necessary. This solution is only possible if the intersection is not overloaded with cyclists. Cyclists cross the intersection. So there should be enough space to pass each other at 1.5 metres. This is a software change and often it is also necessary to do something physical with the intersection: think of adapting road signs on the road surface.
- Linking bicycle directions. Follow-up crossings belonging to the same intersection, busy left-turning streams and busy bicycle streams across multiple intersections may be linked. By harmonising the green moments of the various bicycle crossings, fewer cyclists will arrive at the traffic lights during the red phase. And there are fewer problems waiting at a distance for green. Linking different bicycle directions may cause the handling of motorized traffic to deteriorate. This can sometimes be adjusted with parameters, but is usually a software change.
- In the case of intelligent Traffic Light Controllers (Dutch: iVRIs), a higher priority may be set for bicycle signal groups, so that bicycle directions become more important and are included more heavily in the allocation to the next direction to turn green.
Longer Green Times for Cyclists
Long green times are needed to be able to handle queues of cyclists. As the queue of cyclists requires a further distance (lower capacity), a longer green time is needed to be able to handle the same number of cyclists. In addition to fine-tuning the correct green times for settling the queue, an even longer green time for cyclists can also be used to increase the number of arrivals during green phases. When arriving during a green phase, cyclists do not have to stop or choose a position to stand 1.5 metres away from other cyclists.
- For bicycle signal groups without (extended) detection this means that a higher green time for the bicycle signal group can only be achieved with a higher setting of the fixed green time. A higher fixed green time setting has a rigid character. The same long green time is always made, whether one or 20 cyclists want to ride Fixing times are often not time-dependent. This means that even during the different periods of the day, during rush hour or in the middle of the night, the same green time is always made. This is a parameter change.
- For bicycle signal groups with (extended) detection, the maximum green time can be increased per period of the day as required. Here it is important to also set the gap times of the bicycle signal groups higher. As the distance between cyclists is greater, a higher gap time is necessary to give cyclists the opportunity to occupy the detection loop again after the loop’s predecessor has been driven off. With a higher gap time it is also possible to keep the green time longer so that arrivals during green will be increased. This is also a parameter change.
- More attention for bicycle couplings. By coupling bicycle signal groups hard or soft, the number of stops for cyclists can be reduced. Where possible, bicycle couplings can be fitted internally within one arrangement. But where possible also between different Traffic Light Controllers . For this the software has to be changed.
- With an intelligent Traffic Light Controller (iVRI), an arriving cyclist can be detected at a greater distance from the stop line by means of an app, and the controller can keep the cycling direction green for arriving cyclists, or steer to green at the right moment. This also reduces the number of stops for cyclists. This is a software change.
Alternative: Other Use of Road Space
In addition to adjusting the traffic light controller, road authorities may consider creating more space for cyclists outside the current cycling infrastructure. Think of shared use of the carriageway. In order to guarantee road safety, additional measures for cars and public transport will then be necessary. Consideration could also be given to fully allocating the current car and/or public transport infrastructure as bicycle infrastructure. This requires a network-wide approach so that certain (parts of) roads can only be designated as bicycle infrastructure and other parts of the traffic network exclusively for motorised traffic.
Create Temporary One-Way Cycle Paths
In many cases a bi-directional bicycle path causes a strong decrease in capacity. On cycle paths of this kind, it is not possible to set up cyclists next to each other as a sort of herringbone. Setting up at the edge of the bike path causes problems with the 1.5 metre space in the opposite direction. Wherever possible, the two-way bike path can be removed by only allowing one-way cycling.
Pedestrians and Cyclists Spaced Apart
Tight footpaths right next to cycle paths can also cause problems to ensure the 1.5 metre distance between all road users. Here too, the different use of the existing infrastructure can provide a solution. Using the footpath in only one direction is possible, but a solution can also be found in, for example, moving the pedestrian to the bike path and moving the cyclist to the carriageway.
Infrastructural Adaptations
Road authorities could also make more space within the current cycling infrastructure. By rearranging escape mounds and lines according to the “banana” and “chip bag” principles, more space can be created for cyclists to line up next to each other rather than behind each other. This will benefit the queue length and more cyclists can be settled within the same green time. These choices are comparatively expensive and especially advisable when such an adjustment fits in with long-term policy.
Finally…
- For the time being, it is stated that the risk of contamination via push buttons is nil. In order to accommodate cyclists and pedestrians, fixed requests can be made. Various road authorities have already applied this. It would then be wise to point this out to cyclists (for example with a sticker), so that they do not touch the push buttons after all.
- In case of a large main stream of cyclists with priority, it may be considered to temporarily switch off the traffic lights. Cyclists would then no longer have to stop and thus there would be fewer problems with setting up. This is only possible if directions of conflict are calm and road safety is not compromised.
- A system like Evergreen ensures that all cyclists can drive through green. Here too the solution lies in the fact that cyclists do not have to stop and therefore there are no set-up problems.