Abstract
The numbers of accidents by day and by night during the campaign have been compared with those in the corresponding period one year earlier. Accidents on roads where the more important street lighting changes had been made (about 14 percent of all accidents) have been omitted from the main analysis because it is known that such improvements result in a reduction in accidents at night, and the month of March has been omitted because a similar but shorter campaign was held in Birmingham in March, 1962. Accidents on one-way streets (about 3 per cent of the total)have also been omitted.