Single/Double British Summertime Factsheet

  • Published: The Royal Society for the Prevention of Accidents (RoSPA), 2012
  • Authors: The Royal Society for the Prevention of Accidents (RoSPA)
  • Date Added: 18 Mar 2013
  • Last Update: 12 Feb 2016
  • Format: pdf


To summarise the evidence about Single Double British Summertime



Key Findings:

  • In the UK, clocks follow Greenwich Mean Time (GMT) from October to March and British Summer Time (BST) which is GMT + 1 hour from March to October. Most of Europe follows Central European Time, which is one hour ahead of GMT in winter and 2 hours ahead of GMT in summer – always one hour ahead of the UK.

  • One of the consequences of the UK’s system is that more people are killed and injured on the road because of darker evenings in the autumn and winter than would be if we adopted Single/Double British Summertime (SDST).

  • During the working week, casualty rates peak at 8am and 5pm for adults and 8am and 3.30pm for children, with the afternoon peak being higher for both. Road casualty rates increase with the arrival of darker evenings and worsening weather conditions.

  • Every autumn when the clocks go back and sunset occurs earlier in the day, road casualties rise. The effects are worse for the most vulnerable road users like children, the elderly, cyclists and motorcyclists.

  • In 2011, pedestrian deaths rose from 25 in September, to 34 in October, 48 in November and 65 in December. The overall casualty rate increased from 667 per billion vehicle miles in September to 708 per billion vehicle miles in December.

  • The relative peaks are explained by several factors, including:

    • Motorists are more tired after a day’s work and concentration levels are lower;

    • Children tend to go straight to school in the morning but often digress on their way home, increasing their exposure to road dangers;

    • Adults tend to go shopping or visit friends after work, increasing their journey times and exposure to road dangers; and,

    • Social and leisure trips are generally made in the late afternoons and evenings.

  • Moving to SDST would produce significant net benefits – although there would be a slight increase in the morning RTI peak, this would be more than offset by the reduction in the higher evening peak.

  • The most recent research estimates that adopting Single/Double Summer Time would have the net effect of saving around 80 lives and 212 serious injuries a year confirming earlier research which showed that the 1968/71 experiment, when British Standard Time (GMT + 1) was employed all year round (the clocks were advanced in March 1968 and not put back until October 1971) saved around 2,500 deaths and serious injuries each year of the trial period.

  • In 2009, the Department for Transport’s consultation paper, ‘A Safer Way: Making Britain’s Roads the Safest in the World’, confirmed that moving to lighter evenings would prevent about 80 deaths on the road a year. There would be a one-off cost of about £5million to publicise the change but then benefits of around £138million per year.

  • Also in 2009, the National Audit Office published ‘Improving Road Safety for Pedestrians and Cyclists in Great Britain’. In a section looking at seasonal road casualty patterns from 2000-2007, the report stated that there were 10 per cent more RTIs killing or injuring a pedestrian in the four weeks following the clocks going back than in the four weeks before the clocks changed.

  • In the past, a move to SDST has been opposed by those industries whose workers rise early and utilise morning light, for example some farmers, those who collect and deliver milk, the building industry and postal workers. There is now increasing evidence that these objections are less relevant.

  • In Scotland, there has been opposition to the change. A 2005 MORI poll suggested that only 40 per cent of Scots were in favour of the change.

  • Opinions in Scotland seem to be changing.

  • The most recent attempt to change Britain’s legislation about lighter evenings was Rebecca Harris MP’s Private Members’ Bill, ‘Daylight Savings Bill’, which would have required the Government to conduct a cross-departmental analysis of the potential costs and benefits of advancing time by one hour for all, or part of, the year. If the analysis finds that this would benefit the UK, a trial would be conducted and evaluated to finally determine the full effects. Unfortunately, despite having significant support in Parliament and getting much further through the parliamentary process than any other Private Members’ Bill on this topic, the Bill was talked out by a small number of MPs at its Third Reading on 20 January 2012.

  • RoSPA recommends that a change to lighter evenings should be introduced on a trial basis for 2- 3 years. This would provide objective, up-to-date evidence about the effects of SDST and also enable the public and the various industry and business sectors that would be affected to experience the change for themselves.


Daylight Savings Bill, SDST, Road casualty rates.