Citation

Cyra DJ. Highw. Res. Rec. 1971; 37: 28-39.

Copyright

(Copyright © 1971, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

In April 1969, the wisconsin department of transportation conducted a comprehensive traffic study on the freeway with the highest volume in the state. This input-output study consisted of manually recording volumes and speeds during peak periods over a 5 1/2- mile freeway section. Vehicle accumulation and speed data were collected and processed. An aerial study using time-lapse photography collected similar data during the same peak period. Oblique aerial photography was used to collect vehicle accumulation data, and vertical aerial photography was used to collect vehicle speed data. Statistical analyses were made to determine the reliability of the aerial photographic collection techniques as compared to the conventional collection procedures. In addition to method reliability, actual cost comparisons were made which indicated that oblique aerial photography is a reliable and economical method for collecting vehicle accumulations and that vertical photography is a reliable method for collecting vehicle speeds and headways. The vertical method allows traffic flow evaluation based on the performance of individual vehicles in the traffic flow evaluation based on the performance of individual vehicles in the traffic flow but is an expensive method of collection when only speed data are considered. However, when data on vehicle accelerations, headways, and platoon behavior are required, vertical photography is convenient and economical as well. /author/

Language: en

Keywords

TRAFFIC SURVEYS; AERIAL PHOTOGRAPHY; PHOTOGRAPHY-Aerial