Citation

Mounce JM. Transp. Res. Rec. 1984; 957: 28-30.

Copyright

(Copyright © 1984, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Priority entry ramps are a transportation system management technique implemented to provide travel time savings to high-occupancy vehicles delayed in access to freeway main lanes because of congestion. The effectiveness of priority entry ramps is diminished as violations by unauthorized, lowoccupancy vehicles increase. Violations on priority entry ramps were analyzed from data collected at two sites in Houston. The results indicate an approximate, average violation rate that exceeds 40 percent when no enforcement is present. The results of random, intermittent enforcement indicate a decrease in violations to an approximate average rate of 15 percent. The priority entry exposure ratio, which is defined as service time of nonpriority vehicles divided by the arrival time headway between priority vehicles, was also determined to be an influencing factor on violation rate. For the limited data within this study, a linear equation was statistically established to predict a decrease in ramp violations as the priority entry exposure ratio increases. A graphical illustration of this relationship is presented to allow determination of enforcement requirements for priority entry ramps.

Record URL:
http://onlinepubs.trb.org/Onlinepubs/trr/1984/957/957-006.pdf

Language: en

Keywords

HIGHWAY TRAFFIC CONTROL; HIGHWAY SYSTEMS; STATISTICAL METHODS - Applications