The effect of traffic signal strategies on the safety of pedestrians

TRL was commissioned by the Department for Transport (DfT) to consider the effect of signal control strategies on casualties, particularly for pedestrians and to provide input into the decisions faced by practitioners in optimising the split between safety and delay.

A literature review was undertaken to determine what research had been undertaken to date.

Some instances of poor pedestrian behaviour were discussed by focus groups in order to gain insight into the underlying reasons.

A total of 16 signal-controlled junctions and six mid-block crossings with different forms of signal control were selected as case studies. Details of the junction or crossing layout and signal timings were recorded. A four hour video survey was undertaken at each site and flow counts and extensive behavioural analysis undertaken.

Alternative strategies were then tested and any changes in pedestrian behaviour evaluated. TRANSYT modelling was undertaken to investigate the trade-off between vehicle and pedestrian delay.

One of the key objectives of the project was to provide advice to local highway authorities regarding the application of signal control strategies.

Given that the results from the work did not indicate any strong relationship between signal control strategy and safety, guidance will necessarily be based as much on common sense and experience as on specific safety issues.

However, there is an implication that seeking to increase pedestrian compliance with the signals is desirable. Increasing compliance is likely to be achieved mainly by reducing pedestrian waiting times.