Citation

Wynn FH. Highw. Res. Board bull. 1956; 119: 53-68.

Copyright

(Copyright © 1956, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A synopsis is presented of studies on automobile travel within the urban limits of american cities. Tabulations and other home-interview materials were obtained from about 60 cities, and studies which appear to be most complete and which require the least adjustment were selected for further analysis. An attempt was made to find the principle cause of work-trip deviations by mode. Studies show that city size has a consistent effect on the generation of travel within a city, being directly related to volume of trips generated by purpose (work) and by mode of travel (auto or transit). The daily rate of central-business- district trip generation is shown to deteriorate rapidly as distance from central business district increases. When trips generated in the central business district for all purposes are plotted by mode against length, several interesting relationships appear. Trips by each mode tend to be generated at a lower rate as distance from a central business district increases. However, trips by transit drop off much more rapidly than auto-driver trips. The ratio of persons to cars, to length of trip, and to trips per car account for much of the variablility of auto- trip attraction to the central business district. Four important independent variables have been identified which relate to the generation of internal auto trips in the central business districts: (1) the average number of trips made to and from the central business district each, by each car garaged in the metropolitan area is related to the average distance of travel, (2) the number of persons per car in each area, (3) the proportion of the urban area population that is concentrated within various increments of distances from the central business district, and (4) the total number of people resident in the metropolitan area. Charts are presented which show the relative effects of these variables.