STOP!

STOP! is a collaboration between Professor Steve Fotios (University of Sheffield) and Professor Nick Tyler (UCL). STOP! will combine their respective expertise of research in lighting for pedestrians and pedestrians’ interactions with their environment to investigate road lighting at un-signalled (zebra) pedestrian crossings.

A zebra crossing uses a Belisha beacon to promote conspicuity (in other words, to prompt drivers that there is a pedestrian crossing ahead when they were not expecting it) and overhead lighting to promote visibility of pedestrians on the crossing. Both conspicuity visibility are important if drivers are to take action (to slow down and possibly stop) in sufficient time.

An analysis of the effect of light and dark on road traffic collisions at pedestrian crossings (Uttley and Fotios 2017) reveals a problem: the risk of a pedestrian RTC after dark is greater at crossings than at non-crossing locations. This analysis used an odds ratio approach so effects of time of day and pedestrian flows are accounted for. What it suggests is that either pedestrians are over-confident of their visibility to drivers (as found by Joanne Wood and Rick Tyrrell in their studies) or that pedestrian crossings do not offer sufficient visibility and conspicuity to approaching drivers.

While it may be expected that lighting criteria for pedestrian crossings is based on robust empirical evidence, that does not appear to be the case: sources of guidance from around the world disagree on what light level should be used and where it should be measured. The Institution of Lighting Professionals has established a technical committee to review lighting design at pedestrian crossings. One conclusion from a recent meeting (March 2019) is that there is a need to consider a radical redesign of pedestrian crossings and not merely tweak the design targets.

Fotios and Tyler plan to investigate this using laboratory and field studies. Using the scale model simulator developed at Sheffield University for work with Highways England we will explore visibility and conspicuity under variations in lighting characteristics and with different types of lighting systems. At UCL’s PEARL laboratory we will construct a full-scale zebra crossing to investigate pedestrian perception of visibility to drivers and the impact of different lighting conditions on glare imposed to pedestrians and drivers.

We have also arranged for a long term field trial so that pedestrian crossing and driver yield behaviours can be monitored. This will be done after the laboratory studies so that the field trial can be designed following evidence of best solution(s).