Using the daylight savings clock change to show ambient light conditions significantly influence active travel

- Biannual clock changes used to compare active travellers in daylight and dark.
- Daylight increased pedestrian numbers by 62% and cyclist numbers by 38%.
- Effect of light remained after accounting for temperature and precipitation.
- Effect of light on cyclists varied depending on cycling infrastructure used.
- Highlights potential for outdoor lighting to influence active travel behaviour.

This article reports a novel procedure used to investigate whether ambient light conditions affect the number of people who choose to walk or cycle. Pedestrian and cyclist count data were analysed using the biannual daylight-saving clock changes to compare daylight and after-dark conditions whilst keeping seasonal and time-of-day factors constant. Changes in frequencies during a 1-h case period before and after a clock change, when light conditions varied significantly between daylight and darkness, were compared against control periods when the light condition did not change. Odds ratios indicated the numbers of pedestrians and cyclists during the case period were significantly higher during daylight conditions than after-dark, resulting in a 62% increase in pedestrians and a 38% increase in cyclists. These results show the importance of light conditions on the numbers of pedestrian and cyclists, and highlight the potential of road lighting as a policy measure to encourage active travel after-dark.