The influence of vehicle weight on the risk of injury to drivers.

THE RESULTS OF ANALYSES OF THE NATIONAL ACCIDENT STATISTICS FOR GREAT BRITAIN FOR THE YEARS 1969-1972, PUBLISHED IN 1979, ARE SUMMARISED WITH SOME ADDITIONAL MATERIAL. THE EFFECT OF THE RATIO OF THE WEIGHTS OF THE COLLIDING VEHICLES (THE MASS RATIO) IN TWO-VEHICLE ACCIDENTS ON THE SEVERITY OF INJURY TO THE DRIVERS OF THE VEHICLES WAS DETERMINED, SEVERITY BEING JUDGED BY THE PERCENTAGES OF FATAL, SERIOUS AND SLIGHT INJURY AND OF UNINJURED DRIVERS. THE COLLIDING VEHICLES INCLUDED IN THE ANALYSIS RANGED IN WEIGHT FROM THE LIGHTEST CARS (KERB WEIGHT ABOUT 800 TO 1700 LB - 350 TO 800 KG) TO HEAVY COMMERCIAL VEHICLES WEIGHING UP TO 30000 LB (13608 KG). SEPARATE ANALYSES WERE MADE FOR HEAD-ON AND INTERSECTION COLLISIONS, BOTH IN RURAL AND URBAN AREAS. WITH SINGLE-VEHICLE ACCIDENTS, THESE COLLISIONS ACCOUNT FOR MOST OF THE FATAL AND SERIOUS INJURIES IN CARS AND COMMERCIAL VEHICLES. IN BOTH TYPES OF COLLISION MASS RATIO WAS FOUND TO HAVE ITS GREATEST EFFECT ON DEATHS AND LEAST ON SLIGHT INJURIES. FOR EXAMPLE, WHEN ONE OF THE VEHICLES IN EACH OF A NUMBER OF HEAD-ON COLLISIONS WAS TWICE THE WEIGHT OF THE OTHER, THE PERCENTAGE OF DEATHS IN THE LIGHTER VEHICLES WAS ABOUT 7 TIMES THAT IN THE HEAVIER VEHICLES. FOR SERIOUS INJURIES THE RATIO OF THE PERCENTAGES WAS ABOUT 3. THE RATIOS FOR ALL SEVERITIES OF INJURY WERE RATHER HIGHER IN URBAN THAN IN RURAL AREAS. THE EFFECT OF MASS RATIO IN INTERSECTION ACCIDENTS WAS SIMILAR TO THAT IN HEAD-ON COLLISIONS. THE RELATION OF INJURY SEVERITY TO VEHICLE WEIGHT IN COLLISIONS IN WHICH THE TWO VEHICLES WERE OF APPROXIMATELY EQUAL WEIGHT (MASS RATIO 0.95 TO 1.05) WAS EXAMINED, AND NO EFFECT OF WEIGHT IN REDUCING DEATHS OR SERIOUS INJURIES WAS FOUND EITHER IN HEAD-ON OR INTERSECTION COLLISIONS; THERE WAS SOME INDICATION OF AN INCREASE IN THE PERCENTAGE OF DEATHS IN COMMERCIAL VEHICLES WITH WEIGHTS OF 6000 TO 30000 LB (2722 TO 13608 KG). IN SINGLE-VEHICLE ACCIDENTS, WHETHER THEY WERE OF THE OVERTURNING OR NON- OVERTURNING TYPE, THERE WAS LITTLE OR NO EFFET OF VEHICLE WEIGHT.(A) FOR THE COVERING ABSTRACT OF THE CONFERENCE SEE IRRD 802816.