Design and Build Signalised crossings

  1. Plan
  2. Design and Build
  3. Sell
  4. Evaluate

Considerations

  • The traffic light programme determines the chance of stopping and waiting times, which in turn affects the number of interruptions and travel time.
  • The conflicts allowed in the programme (e.g. between bicycles going straight and motor vehicles turning left and/or right) usually represent a trade-off between safety and waiting times.
  • Usually there is also room for discretion (depending on legal framework) when determining how many conflict points on an intersection are signalised. E.g. one might decide whether to use traffic signals or not to regulate the traffic of pedestrians crossing a cycle path.
  • Adequate space – e.g. additional width – needs to be provided to accommodate cyclists waiting for green light so that they do not obstruct other traffic (perpendicular cycle traffic, pedestrians, motor vehicles). The longer the wait, the more space you need!

Remedial measures

Several measures can be applied to improve directness, safety and comfort of cycling across a signalised crossing:

  • “Green wave” for cyclists– synchronising subsequent traffic lights to match cycling speed, e.g. 20 km/h. Note that this does not automatically exclude parallel synchronisation for faster traffic, see case study below.
  • Green light optimal speed advice (GLOSA)– additional signalisation in between crossings informing cyclists whether they should speed up, slow down or maintain current speed to reach the next signalised intersection in the green light window.
  • Dynamic information about the fastest route – in case of having several options to negotiate traffic lights or a few subsequent traffic lights, you can provide dynamic information on which route variant includes least waiting time.
  • Early release for cyclists – cyclists getting green light a few (e.g. 4) seconds earlier than motorised vehicles. It improves the recognisability of cyclists for drivers (it is easier for drivers to see cyclists at the conflict point when they are already on a junction, rather than when they are entering it from a side).
  • Bike boxes/advanced stop lines – allow cyclists to accumulate in front of cars during the red light and then leave the crossing quickly as soon as the light turns green.
  • Diagonal cycle crossings – where many cyclists are turning or switching to the other side of a main road, or as a transition between unidirectional cycle lanes or paths on both sides of the road and bidirectional path on one side. Diagonal crossings allow cyclists to stop only once instead of twice, on two legs of the junction and can be integrated with left/right turning phases for motor vehicles.
  • “All green” phase for cyclists – all cycling directions are given a green aspect simultaneously. Useful for crossings with high volumes of cyclists (>10%) turning in the direction opposite to the kerbside. The downside is an increase (in most cases) in the traffic light cycle length.
  • Allowing cyclists to run red lights – on selected junctions, in selected cases. This can be a provisional solution to better accommodate cyclists on a signalised junction that was designed around regulating car traffic.
  • Blindspot (traffic) mirrors – can be placed next to traffic lights to give the driver turning kerbside another chance to notice cyclists coming on a parallel cycle path or lane. The mirror alignment should ensure a good view of a typical lorry blackspot.

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