Citation

Carey RN, Sarma KM. BMJ Open 2017; 7(6): e014319.

Affiliation

School of Psychology, National University of Ireland Galway, Galway, Republic of Ireland.

Copyright

(Copyright © 2017, BMJ Publishing Group)

DOI

10.1136/bmjopen-2016-014319

PMID

28674131

Abstract

BACKGROUND: Bills have been put forward in the UK and Republic of Ireland proposing a move to Central European Time (CET). Proponents argue that such a change will have benefits for road safety, with daylight being shifted from the morning, when collision risk is lower, to the evening, when risk is higher. Studies examining the impact of daylight saving time (DST) on road traffic collision risk can help inform the debate on the potential road safety benefits of a move to CET. The objective of this systematic review was to examine the impact of DST on collision risk.

METHODS: Major electronic databases were searched, with no restrictions as to date of publication (the last search was performed in January 2017). Access to unpublished reports was requested through an international expert group. Studies that provided a quantitative analysis of the effect of DST on road safety-related outcomes were included. The primary outcomes of interest were road traffic collisions, injuries and fatalities.

FINDINGS: Twenty-four studies met the inclusion criteria. Seventeen examined the short-term impact of transitions around DST and 12 examined long-term effects.

FINDINGS from the short-term studies were inconsistent. The long-term findings suggested a positive effect of DST. However, this cannot be attributed solely to DST, as a range of road collision risk factors vary over time.

INTERPRETATION: The evidence from this review cannot support or refute the assertion that a permanent shift in light from morning to evening will have a road safety benefit.

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Language: en

Keywords

collision risk.; daylight saving time; road safety; systematic review