## Abstract

This study has as its objective a determination of whether or not protected left-turning intervals should be provided at a signalized intersection. The basic goal is to achieve minimum delay with maximum safety. Mathematical models have been developed to compute measures of effectiveness for three basic alternatives: no separate left-turning interval, exclusive and permissive left-turning intervals. The basis for all models is the comprehensive methodoloy developed by Webster. Each approach is treated separately and delays to left turns and through movements as well as volume/capacity ratio and number of unsafe turns are calculated. The algorithm proposed here does not provide the engineer with the best solution. It merely presents all the possible alternatives and the associated measures of effectiveness. The choice between the prevailing alternatives must be based on trade-offs between delay and unsafe turns.

Original language | English (US) |
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Journal | Modeling and Simulation, Proceedings of the Annual Pittsburgh Conference |

State | Published - Jan 1 1979 |