Citation

Bonneson JA, McCoy PT. Transp. Res. Rec. 1987; 1114: 74-85.

Copyright

(Copyright © 1987, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

With the release of the 1985 Highway Capacity Manual, a new procedure for analyzing signalized intersections has been introduced. One of the major differences between the 1965 and the 1985 manuals is in the area of left-turn capacity. A general methodology for the analysis of signalized intersections, particularly left-turn operations, is described in the 1985 Manual. Unfortunately, with regard to exclusive left-turn lanes with protected/permitted phasing, the sample calculations provided do not appear to explicitly follow the general methodology. Moreover, the sample calculations introduce many new concepts that are not included in the discussion of the methodology. Calculation 3 in Chapter 9 of the manual is reexamined in this paper. In particular, the left-turn lane groups with protected/permitted phasing are reanalyzed according to the general methodology, but issue is taken with some of the "new" concepts introduced within Calculation 3. On the basis of the findings reported in this paper, it appears that there is a need for some revision of Chapter 9 of the 1985 Highway Capacity Manual, particularly with regard to the analysis of left-turn lane groups with protected/permitted phasing.

Language: en

Keywords

HIGHWAY SIGNS, SIGNALS AND MARKINGS; PROBABILITY - Queueing Theory; TRANSPORTATION - Traffic Control; HIGHWAY TRAFFIC CONTROL - Operations Research