Citation

Drew DR, Pinnell C. Highw. Res. Board bull. 1962; 352: 1-54.

Copyright

(Copyright © 1962, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

The peaking characteristics of signalized urban intersections are investigated. Data on vehicle arrivals were obtained from 60 intersection approaches located in eight major cities in texas. Peak hour studies were conducted during morning and afternoon peaks at selected intersections. Analysis of data indicated the existence of a peak period within the peak hour. The average arrival rates during this peak period greatly exceeded the average arrival rate for the peak hour. The peak period was defined in terms of its duration and magnitude. The duration of the peak period was taken as that interval of time within the peak hour in which the equivalent hourly rate of flow for 5- minute intervals exceeded the peak hourly rate. The magnitude of the peak period was interpreted as the ratio of average arrivals for the peak period to average arrivals for the peak hour. Through a multiple regression analysis based on the sample of 60 intersection approaches, the magnitude of the peak period was expressed in terms of /1/ the population of the city in which the intersection was located, /2/ the location of the intersection with respect to the cbd and the city limits, and /3/ the number of vehicles arriving at the intersection on a given approach within the peak hour. A similar multiple regression analysis showed no significant correlation between the duration of the peak period and the same variables of population, location, and volume. The mean duration of the peak period for all approaches sampled was approximately 26 minutes. The distribution of vehicle arrivals during the peak period and peak hour were analyzed by the chi square test under the hypothesis of a poisson distribution. It was shown that /1/ arrivals during the peak period did conform to a poisson distribution, and /2/ arrivals throughout the entire peak hour did not conform. Finally, some of the aspects of the capacity-design analysis of an intersection are considered in light of these findings. new design and signalization procedures are developed based on vehicle arrivals during the peak period