Selection Criteria for Left-Turn Phasing, Indication Sequence, and Auxiliary Sign
-
1993-02-01
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final Report September 1990 - February 1992
-
Corporate Publisher:
-
Abstract:The report documents the development of guidelines and recommendations for the selection of the left-tum phasing, indication sequences and auxiliary signs. The guidelines developed are based on field studies of over 100 intersections in nine Texas counties and utilize easy to obtain data for the selection process. A three-level decision process regarding the suitability of left-turn phasing treatment to be used is established. The process favors the least restrictive permissive left-turn phase unless traffic and geometric conditions warrant the more restrictive protected/permissive or protected only phasing. The guidelines developed are based on threshold values designed to determine what constitute an "excessive" value for any particular decision variable beyond which more restrictive left-turn phasing treatments may be justified. Recommendations concerning signal indications and auxiliary signs are made based on delay, safety and degree of motorists' understanding. The study results show that selection of any particular phasing is a multi-objective process involving a number of factors, and in many cases more than one condition must be met to justify the selection of a particular phase to ensure an optimum solution.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: