Citation

Tolle JE. Transp. Res. Rec. 1976; 567: 56-64.

Copyright

(Copyright © 1976, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Numerous investigations and studies have been performed concerning the spacings and headways of vehicles in the traffic stream. This paper briefly reviews, examines, and tests some of the mathematical models with real world data collected for both two-lane roadways and urban freeways. These testing methods include both graphical fits and statistical fits, and the results are presented, along with conclusions on the appropriateness of the model representations. The results indicate the composite exponential, Pearson Type III, and log-normal distributions best represent conditions; generally the log-normal distributions are the best for a wide range of traffic volumes.