Citation

Pahl J. Highw. Res. Rec. 1972; 409: 17-33.

Copyright

(Copyright © 1972, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

Lane-change frequencies of existing vehicles close to their intended off-ramp and of through vehicles were determined empirically for an 8-, a 6-, and a 4- lane freeway site. The results were obtained for various flow levels and as a function of upstream distance from the off-ramp. The data base used in this study was acquired by a methodology that involved aerial photographic techniques and that resulted in digitized space-time trajectories of all vehicles traversing the study sites. For each studied flow level at the various sites, lane-change frequencies are presented for each lane pair as well as for both exiting and through vehicles independent of lanes. The results show clearly that the greatest frequency of exiting-vehicle lane changes is toward the right lane and that a corresponding increased frequency of through-vehicle lane changes is toward the left lane. At the off-ramp, where the exiting vehicles leave the freeway, through vehicles have been shown to move back toward the right lane and to have high lane-change frequencies. [TRID]

Language: en

Keywords

TRAFFIC SURVEYS; AERIAL PHOTOGRAPHY