Policy Briefing – Single/Double Summertime

  • Published: Parliamentary Advisory Council for Transport Safety (PACTS), 2010
  • Authors: Parliamentary Advisory Council for Transport Safety (PACTS)
  • Date Added: 18 Mar 2013
  • Last Update: 12 Feb 2016
  • Format: pdf


To provide a policy briefing about Single Double Summer Time.



Key Findings:

  • In the UK, clocks are set to Greenwich Mean Time (GMT) from October to March and British Summer Time (BST), which is GMT + 1, from March to October. Most European Countries follow Central European Time (CET) which is GMT + 1 in winter and GMT + 2 in summer.

  • Research shows that a change in Britain’s timekeeping to fall in line with CET, a move often referred to as ‘Single/Double Summertime’, would bring about significant economic, social, environmental and health benefits. One of the major public health outcomes of such a change would be a reduction in the number of people killed and injured on our roads during the winter months.

  • The combination of the sun setting and high numbers of road users results in a significant increase in the numbers of road deaths and in the total number of people killed and seriously injured (KSI) between 3pm and 6pm. The higher number of injury RTIs in the evenings is linked to the compounding effects of darkness, driver fatigue and the increased exposure of children returning from school.

  • When clocks are put back to GMT in October and this ‘rush-hour’ period becomes darker, KSI increases. This rise is particularly observed by the more vulnerable road users. In 2008, pedestrian road deaths rose from 38 in August and 38 in September to 55 in October and 62 in November.

  • Research conducted by TRL in 1998 estimated that the adoption of Single/Double Summertime in the UK would result in a reduction in road user KSI of around 450. Normalised by average casualty reductions since then, the reduction is more likely to be around 270 fewer KSI casualties of which a reduction in deaths of between 74 and 98.

  • In A Safer Way, the DfT confirmed that the cost benefit case in road safety terms is clear, projecting a net present value of implementation of £2,451.71 million over 20 years. It is estimated that the implementation cost would be around £5 million.

  • Opposition to the move has continually been related to traditional opposition which existed among agricultural workers, construction workers and postal workers who preferred light at earlier times of day.

  • In 2004, PACTS and RoSPA produced a position paper on SDST which called for a new trial, similar in length to that held in 1968/71. A trial of this nature, using modern evaluation methods and effective data recording, would provide the evidence with which government could make a decision about the overall benefits to society of SDST.


SDST, Implementation costs, KSI, Cost benefit.


Summarises the main points related to the introduction of SDST and references other research.