DIFFERENT GENERAL SPEED LIMITS IN SWEDEN. EFFECTS ON ROAD ACCIDENTS AND ON VEHICLE SPEEDS

THE EFFECT OF SPEED LIMITS ON ROAD TRAFFIC ACCIDENTS AND ON ACCIDENTS IN DIFFERENT ROAD AND TRAFFIC ENVIRONMENTS WAS INVESTIGATED. THE TOTAL LENGTH OF THE ROAD NETWORK UNDER INVESTIGATION WAS ABOUT 4,500 KM, INCLUDING SOME 2,000 KM OF ROADS WHERE THE SPEED LIMIT WAS 110 KM/H, SOME 250 KM WITH 130 KM/H SPEED LIMIT AND REMAINDER AT 90 KM/H. FOR COMPARISONS WITH CONDITIONS IN ABSENCE OF ANY SPEED LIMITS, USE WAS MADE OF A REFERENCE YEAR, SEPTEMBER 1966 AUGUST 1967. INFORMATION WAS COLLECTED ON THE ACCIDENTS WHICH HAD OCCURRED IN THE ROAD SYSTEM UNDER INVESTIGATION, ON THE GEOMETRIC DESIGN FEATURES OF THE ROADS, EXPRESSED IN TERMS OF THE WIDTH OF HIGHWAY AND THE WIDTH OF SHOULDERS, ON THE VOLUME OF TRAFFIC, EXPRESSED IN TERMS OF THE AVERAGE DAILY TRAFFIC IN DIFFERENT ROAD ENVIRONMENTS DURING THE PERIODS UNDER INVESTIGATION, ON THE CONDITION OF THE ROAD SURFACE, DESCRIBED IN TERMS OF PRECIPITATION AND TEMPERATURE, AND ON THE ACTUAL VEHICLE SPEEDS. REPEATED COMPARISONS WITH CONDITIONS IN THE ABSENCE OF ANY SPEED LIMITS SHOWED THAT A SPEED LIMIT OF 90 KM PER H HAD A POSITIVE EFFECT ON THE FREQUENCY OF ACCIDENTS. A COMPARISON BETWEEN A SPEED LIMIT OF 90 KM/H WITH THAT OF 110 KM/H WAS MADE BETWEEN THE SUMMER PERIODS OF 1968 AND 1969, AND RELATED TO THE SAME ROADS. THIS IMPLIES THAT THE DIFFERENCES OBTAINED FROM THE COMPARISON IN QUESTION HAD NOT BEEN INFLUENCED BY ANY DIFFERENCES IN THE ROAD STANDARD. IN THIS CASE TOO, IT WAS FOUND BY CHECKING THE RESULTS THAT THE DIFFERENCE IN THE FREQUENCY OF ACCIDENTS REMAINED SIGNIFICANT UNLESS THE ACTUAL INCREASE IN TRAFFIC DIFFERED VERY CONSIDERABLY FROM THAT WHICH HAD BEEN ASSUMED. POSSIBLE EFFECTS OF OTHER FACTORS ON THE RESULTS CAN BE CHECKED BY COMPARING THE ROADS WHERE THE SPEED LIMIT HAS BEEN 90 KM/H IN THE SUMMER OF 1968 AS WELL AS IN THE SUMMER OF 1969. THEREFORE, THE DIFFERENCES BETWEEN SPEED LIMITS OF 110 AND 90 KM/H CANNOT BE ATTRIBUTED IN ANY NOTABLE DEGREE TO DIFFERENCES IN OTHER FACTORS, E.G. SUPERVISION, WEATHER, AND COMPOSITION OF TRAFFIC. VARIOUS COMPARISONS BETWEEN SPEED LIMITS OF 90 AND 110 KM/H SHOWED THAT THE LOWER SPEED LIMIT HAD A POSITIVE EFFECT ON THE FREQUENCY OF ACCIDENTS EVEN WHEN THE CROSS SECTION OF THE ROAD WAS WIDE. /SRIS/

  • Supplemental Notes:
    • Traffic ComMUNICATION NO 90, 10 PP, FIGS
  • Corporate Authors:

    National Road Research Institute /Swed

    ,    
  • Authors:
    • Roosmark, P
    • Nilsson, G
  • Publication Date: 1970

Subject/Index Terms

Filing Info

  • Accession Number: 00226036
  • Record Type: Publication
  • Source Agency: Nat Safety Council Safety Res Info Serv
  • Files: TRIS
  • Created Date: Jun 6 1970 12:00AM