Daylight Hours

Daylight Hours

How Effective?

The British Standard Time Experiment of 1968-1971

An experiment was conducted between 1968 and 1971 to find out the effects of retaining British Summer Time throughout the year.

One of the rare examples of a large scale experiment which affected road safety occurred in the UK between 1968 and 1971, when the system of timekeeping was changed. Clocks were not put back to GMT in the autumn of 1968, so that BST was retained through the winter. The experiment ended in 1971 when clocks were once more put back to GMT in the autumn and the earlier cycle was resumed.

(Broughton and Stone, 1998)

BST was introduced all year round in 1968-71 as an experiment, but its continuation was blocked following a vote in the House of Commons. The main issues raised were morning RTIs and disruption to early morning workers.

(Sillito, 2008)

Research has shown that the 1968-71 experiment saved around 2,500 deaths and serious injuries each year of the trial period. Since the 1968-71 experiment, it is estimated that more than 5,000 people have died and more than 30,000 have received serious injuries in the UK on the roads due to the clocks being put back to GMT each year.

(RoSPA, 2012)

Road casualty figures during the morning (7am-10am) and afternoon (4pm - 7pm) for the period affected by time change in the two winters (1966/67 and 1967/68) before the experiment and in the first two winters (1968/69 and 1969/70) when BST was retained were analysed. The data showed that keeping BST had resulted in an 11 per cent reduction in casualties during the hours affected by the time change in England and Wales and a 17 per cent reduction in Scotland. The overall reduction for Great Britain was 11.7 per cent. Although casualties in the morning had increased, the decrease in casualties in the evening far outweighed this.However it should be noted that the 1968-71 experiment coincided with the introduction of roadside breath tests and the 70mph speed limit, which may have affected the casualty reduction figures.

(RoSPA, 2005)

Gaps in the research

The only way to reach a conclusion about the effects of a move to SDST in this country is to conduct an experiment similar to that held during 1968-71. A trial adoption of SDST over at least two years will provide real data that can allow the changes associated with SDST to be calculated reliably, in terms of casualty reductions as well as other key measures. Such an experiment would give people an opportunity to experience the change for themselves and may be useful in crystallising opinions.

Since the 1968-71 experiment, the road environment and people’s travel habits have changed enormously. Society is more reliant on the car, fewer children walk or cycle to school, opportunities for leisure activities are significantly greater, people take holidays more frequently and overseas travel is much more common. All these factors indicate the need for a new trial of SDST.

(RoSPA, 2005)

  • Date Added: 03 Apr 2012, 08:13 AM
  • Last Update: 27 Jan 2017, 03:58 PM