UNITED STATES RAILWAY TRAFFIC: AN UPDATE

Recent decades have seen changes in the pattern of rail traffic in the United States. This article describes the development of a United States railroad map depicting current levels of traffic on all rail lines handling over five million gross tons per year. This traffic pattern is compared with the 1929 traffic levels appearing on a similiar map developed by Edward Ullman. Revenue ton-miles have nearly doubled since 1929, with most of the increases concentrated on western and southern lines. Traffic on eastern lines has increased only slightly above 1929 levels.