Analysis has been made of the changes in road accident rates up to July 1975 following fuel conservation measures imposed by the UK government since November 1973. Predictions have been made, based on trends and variations observed in past accident rates, of the rates that would have occurred in the absence of the fuel shortage. Comparison of the observed rates with these predictions measures the extent of any changes that have occurred. There were statistically significant reductions in accident rates on motorways and all-purpose roads normally with speed limits of 50 mile/h or higher during the period December 1973-spring 1974, while these roads were subject to 50 mile/h speed limits. There was no similar reduction on roads subject throughout to lower speed limits. After the limits were returned to 'normal', in spring 1974, there was still a reduction in accident rates on 'high-speed' roads, but of a much smaller magnitude than during the speed limit period. The re-introduction of lower limits in December 1974 does not appear to have been associated with as large an effect on accident rates as the limits of the previous winter. The reduction in accident rate from that predicted on the roads subject to the new limits was statistically significant for the first three months. After February 1975 the accident rates were not significantly different from those expected. It has not been possible to make an entirely satisfactory analysis of the effects of the street-lighting cuts in winter 1973-74, since the roads on which the lighting condition changed cannot be isolated for separate study. Analysis of accident rates on all urban roads in darkness does not demonstrate overall an adverse effect of the cuts, though variations in effect between different types and locations of accident may be masked. (Author/publisher)
Abstract