Citation

Heikal A, Nemeth Z. ITE J. 1985; 55(6): 22-24.

Copyright

(Copyright © 1985, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

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.