Citation

Goldblatt RB. Transp. Res. Rec. 1980; 773: 24-31.

Copyright

(Copyright © 1980, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

This paper presents the results of an investigation into the effect of changes in location of freeway traffic sensors on incident detection. The study was performed with a microscopic freeway computer-simulation model called Integrated Traffic Simulation (INTRAS). Two measures of effectiveness were employed in the study--the detection ratio and the average time to detect (assuming that detection occurs). Consideration was also given to false alarms. A total of four geometric features was studied: (a) main-line sections, (b) weaving sections, (c) lane drops and additions, and (d) changes in vertical and horizontal alignment.

RESULTS of the study indicated that freeway sensors should be located between 305 and 762 m (1000 and 2500 ft) apart. Decreasing the spacing to 152 m (500 ft) increases the false-alarm rate with little improvement in detection time.