Abstract
A simple quality control technique is applied to sections of road of uniform geometries and traffic flow. Such sections as have inordinately high accident numbers relative to sections in the same traffic volume group are designated `black' or `out of control' sections. Some 2,700 miles of road are covered, on which 3,800 fatal and personal injury accidents and 9,350 accidents in total were reported as occurring for years 1968, 1969, 1970. The method used isolated some 220 miles of road with almost 1,000 fatal and personal injury accidents for further study.