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Citation |
Sofokidis H, Tilles DL, Geiger DR. Highw. Res. Rec. 1973; 453: 28-48. |
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Copyright |
(Copyright © 1973, National Research Council (U.S.A.), Highway Research Board) |
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DOI |
unavailable |
PMID |
unavailable |
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Abstract |
The purpose of this study was to evaluate two intersection-delay measurement techniques. As a result of an extensive literature review, two methods were chosen to be the most practical for field application: The sagi-campbell method, which determines "aggregate" intersection delay from measurements of inflow, outflow, and length of queues at various points during each cycle, and the berry-van til sampling method, which measures stopped delay counts of the number of stopped vehicles at predetermined time intervals. A two-lane intersection approach in arlington,virginia, was recorded on closed-circuit real-time television and filmed simultaneously on time-lapse super-8 movie film for four 1-hour periods. Traffic conditions varied from extremely low to very high saturated flow. Data were extracted while video tapes were played back. Delays computed from the time-lapse photography were used as bases for comparison of results from either of the two test methods. In addition, results by the sagi-campbell method were compared with delays measured by the traffic flow meter. Relations between volume and delay and queue length and delay were investigated. Neither one of the methods produced consistent trends in predicting delays as compared to the traffic flow meter or photographic methods used as bases. Even the base methods failed to give consistent, direct relations. Language: en |
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Keywords |
TRAFFIC SURVEYS; STREET TRAFFIC CONTROL; TELEVISION SYSTEMS, CLOSED CIRCUIT |