Citation

Lu JJ, Lall BK. Transp. Res. Rec. 1995; 1495: 49-56.

Copyright

(Copyright © 1995, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

In the United States, the current capacity estimation procedure of two-way stop-controlled intersections is based on the German guidelines. Professionals in the transportation field have called for a modification of this procedure or for development of new procedures verified by U.S. field data. A research study sponsored by Region 10 of the U.S. Department of Transportation University Transportation Center was undertaken to study traffic characteristics at two-way stop-controlled intersections, including delay, capacity, and gap acceptance characteristics. Field data were collected from six test sites in Fairbanks, Alaska. For the analysis of delay and capacity characteristics, about 34 hr of traffic data were recorded in 17 videotapes. Data average intervals of 5- and 15-min were used to reduce field data by using a specialized computer program, called Traffic Data Input Program. The main purpose for using this program was to obtain summarized traffic data from the videotapes with certain average intervals (5 and 10 min), such as service delay, queue delay, major traffic volume, minor traffic volume, movement distribution, and so on. For the gap acceptance data, observers reviewed field pictures shown on a TV set and manually collected the accepted gap data. Researchers used empirical methods to develop regression models that characterize the statistical relationships between service delay and conflicting volume, minor street capacity and conflicting volume, and total delay and minor and conflicting volumes. Researchers used linear, negative exponential, and nonlinear two-variable functions, respectively, to fit these models. Reasonably good fitness of these models resulted and modeling results showed that the major street speed limit did not significantly affect these models. Concerning driver's gap acceptance behavior, the field data were collected to quantify the relationship between service delay and critical gap. Researchers in this field have assumed that minor-street drivers tend to accept smaller gaps as they wait a longer time at the stop line or in queue.

RESULTS obtained from this study verified the assumption and researchers obtained a quantitative model to quantify the relationship.

Language: en

Keywords

Intersections; Mathematical models; Traffic signals; Highway traffic control; Computer software; Statistical methods; Computer aided analysis; Data reduction