ACCIDENTS AND OPERATIONAL CHARACTERISTICS ON ARTERIAL STREETS WITH TWO-WAY MEDIAN LEFT-TURN LANES

THE NEED TO EXPEDITE THROUGH TRAFFIC AND STILL PROVIDE ADEQUATE ACCESS TO ABUTTING PROPERTIES RESULTED IN THE IN- STALLATION OF THE FIRST TWO-WAY MEDIAN LEFT-TURN LANE/2WLTL/ BY THE CITY OF SEATTLE IN NOVEMBER 1952. BRIEF STUDIES CONDUCTED BY THE TRAFFIC ENGINEERING DIVISION INDICATED THAT THE 2WLTLS FACILITATE THE MOVEMENT OF THROUGH TRAFFIC AND PROVIDE A HIGH DEGREE OF ACCESS SERVICE, YET THEIR USE HAS NOT RESULTED IN AN INCREASE IN TRAFFIC ACCIDENTS. THIS STUDY CONSIDERED THE EFFECT OF THE 2WLTL ON ACCIDENT EXPERIENCE ALONG STREETS SERVING COMMERCIAL AND INDUSTRIAL AREAS. TRENDS IN ACCIDENTS, ACCIDENT RATES, TYPE OF MOTOR- VEHICLE COLLISIONS AND ACCIDENT SEVERITY WERE CONSIDERED. IT IS INDICATED THAT PROPER USE OF THE 2WLTL CAN AID IN THE REDUCTION OF ACCIDENTS OR AT LEAST HELP TO ATTENUATE INCREASES IN ACCIDENTS WHEN TRAFFIC VOLUME AND PROPERTY DEVELOPMENT INCREASE. PROPERTY DAMAGE AND INJURY APPEAR TO BE LESS SEVERE FOR THE 2WLTL THAN FOR NON-2WLTL ACCIDENTS. MORE EFFECTIVE SIGNING AND/OR MARKING OF THE 2WLTL ARE NEEDED TO INSURE ITS PROPER USE BY UNFAMILIAR DRIVERS. IN ADDITION TO PROVIDING FOR MIDBLOCK AND INTERSECTION LEFT TURNS, THE 2WLTL ALSO PROVIDES FOR REFUGE AND SEPARATION FUNCTIONS. IN ACTUAL OPERATION IT IS USED FOR MANY OF THE EMERGENCY FUNCTIONS OF A MEDIAN SHOULDER AREA, INCLUDING DETOUR ROUTES WHEN UTILITY CUTS AND STREET MAINTENANCE ARE NECESSARY.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 20-56
  • Monograph Title: Traffic control
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00203097
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Dec 12 1994 12:00AM