Citation

Johnson AN. Highw. Res. Board Proc. 1930; 10: 218-224.

Copyright

(Copyright © 1930, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A traffic study was made to determine the relative capacity of two-lane, three-lane, and four-lane road-ways. congestion was defined as that which occurs on a road when the number of vehicles is great enough to fill the road and make turning out impracticable and this condition must last a sufficient time to be noticeable. Traffic counting results are presented in a table. The following conclusions are drawn from the data presented: (1) the two-lane road is practically free from congestion up to 1,000 vehicles per hour, (2) the three-lane road is practically free from congestion up to 1600 vehicles per hour, and is congested not to exceed one-fifth of the time up to 1900 vehicles per hour, (3) with further increase in the number of vehicles per hour, congestion increases at a more rapid rate on a two-lane road than on a three-lane road, and (4) when four-fifths or more of the traffic is in one direction, the two-lane road is practically free from congestion up to 1300 vehicles per hour, and the three-lane road up to 2300 vehicles per hour.