Civil Engineering Reference
In-Depth Information
Chapter 3
Historical Perspective of Urban Traffic
Congestion
3.1 Introduction
Congestion is not new. It predates the industrial revolution, the motor vehicle, and
the modern city. It was common in ancient time, in 17th century London, and in
19th century New York. The produce markets, port areas, and downtowns of
yesteryear all were overcrowded and congested.
The industrial city that grew before the automobile era experienced traf
c
congestion caused by high population and employment densities that produced
travel demands in excess of road capacity. The emergence of skyscrapers in late
19th century, coupled with the mix of horse-drawn vehicles created severe con-
gestion during the latter years of the 19th century.
Before the automobile and electric railways, congestion was mainly limited to
city centers and their immediate environs. Traf
c congestion now permeates the
metropolitan area [
1
].
The geographic spread of congestion over the past century is illustrated in
Fig.
3.1
. This dispersion re
ects improved transportation mobility and its impact on
suburban development patterns.
fl
3.2 Historical Examples
Traf
ected city size and structure. Modes, loca-
tions, and intensities have changed over the years, but the common themes remain
c congestion has consistently re
fl
—
the concentration of people and vehicles in major employment centers, and the
inability to manage the con
icts among competing travelers and road users, and to
eliminate physical obstructions to movement [
2
].
Before the automobile era, congestion was characterized by stagecoaches,
wagons, and pedestrians vying for downtown space. The street railway, introduced
fl
