The two-way left-turn lane (TWLTL) is often a practical treatment to midblock left-turn problems along an arterial. The TWLTL provides refuge for midblock left turners. On arterials without TWLTLs, midblock left turners can have a very detrimental effect on the quality of flow by creating delays and forcing other drivers to change lanes. No generally accepted method exists by which this effect can be measured. The purpose of this article is to suggest an approach to determine the degree of congestion along arterials with midblock turning movements. A microscopic arterial simulation model (ARTSIM) has been developed by Heikal utilizing the discrete-event simulation discipline to predict the operational effects of the TWLTL. The ARTSIM model simulates traffic operations on a two-way two-lane and a two-way four-lane arterial with and without a TWLTL. The ARTSIM simulates behavior of vehicles in various situations: free-flow, car-following, left-turn maneuvers and lane changes. The model generates statistics of the following measures of effectiveness: travel time, number of stops, stopped-delay time, and number of lane-change maneuvers. Other secondary measures of effectiveness such as fuel-consumption rates and the number of panic decelerations are also provided. To check the validity of the model, Heikal conducted several tests. The results of the car-following and queue-discharge tests were completely satisfactory.

  • Availability:
  • Corporate Authors:

    Institute of Transportation Engineers (ITE)

    Washington, DC  United States 
  • Authors:
    • HEIKAL, A S
    • Nemeth, Z
  • Publication Date: 1985-6

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Subject/Index Terms

Filing Info

  • Accession Number: 00450768
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: HS-038 936
  • Files: HSL, TRIS, USDOT
  • Created Date: Dec 31 1985 12:00AM