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TRANSPORTATION RESEARCH RECORD 1221
Research in Bus and Rail Transit Operations
Transportation Research Board
National Research Council
Washington, DC 1989
Impact on Transit Patronage of
Cessation or Inauguration of
Rail Service
Edson L Tennyson
Many theorists believe that transit service mode has little
influence on consumer choice between automobile and transit travel. Others
believe that they have noted a modal effect in which rail transit attracts
higher ridership than does bus when other factors are about equal. Given
environmental concerns and the large investment needed for guided transit, a
better understanding of this issue is essential, especially for congested areas.
A consideration of the history of automobile and transit travel in the United
States can be helpful in comprehending the nature of the problem. After World
War II, availability of vehicles, fuel, and tires spurred growth of both private
automobile use and use of buses for transit. Analyses of the effects of both
this growth and the improvements in rail systems that were added during the same
period reveal that transit mode does indeed make a significant difference in the
level of use of a transit facility. This factor must be included in future
alternative analysis studies if reliable patronage determinations are to be
made.
The purpose of this paper is to
analyze what difference (if any) rail transit makes in attracting the public to
use public transportation. Many metropolitan areas in North America suffer
intensifying traffic congestion with no cure in sight, particularly in the
suburban growth areas (1). At the same time, air pollution laws and
problems require a radical reduction in emissions, with no assurance that much
improvement can be accomplished. Diesel transit buses will be among the first
vehicles to be affected by the Clear Air Act in 1991, but the necessary
technology has not yet been perfected. Urban air is still not sufficiently
healthful.
The expanded use of public transit can
sharply reduce the use of automobiles and resulting pollution. The consumption
of only 700 gallons of motor fuel per household in the District of Columbia and
New York State, where there are significant rail transit services in addition to
ubiquitous bus services, is evidence of this. States with the least transit
service consume nearly three times as much motor fuel per household as do states
in which rail transit predominates
(2).
Most traffic- and trip-generation studies
recognize no difference in trip generation attributable to the choice between
rail and bus service, although recent work by R. H. Pratt and the Metropolitan
Washington Council of Governments (3) demonstrates that recognition of
the difference has begun. In estimating commuter rail patronage, Pratt found it
necessary to increase rail estimates 43 percent over calculations for similar
bus service to calibrate models accurately for suburban transit use (4).
Earlier, the Delaware Valley Regional
Planning Commission found that regional models calibrated for 99 percent
confidence level grossly overstated local bus ridership and equally understated
commuter rail ridership to obtain correct regional totals (5). There is
thus considerable anecdotal evidence that transit submode choice can make a
substantial difference in the actual attraction of motorists to transit, with
widespread attendant benefits.
It is true that travel time, fare,
frequency of service, population, density, and distance are all prime
determinants of travel and transit use, but automobile ownership and personal
income may not be consistent factors for estimating rail transit use for people
with a choice. Most bus riders are heavily transit dependent, whereas subway
passengers are less so. Railroad commuters are highly dependent on automobiles
and high incomes to access and use rail service, and they do use it where it is
of high quality (6). The same models do not appear to work accurately for
the different transit submodes, but too few studies recognize the difference.
In this analysis, the historical secular
trend in the transit industry from 1947-1948 to 1975 (when the statistical base
was shifted to unlinked trips) will be examined first, to seek evidence of any
differential in the rate of public use of public transit by submode. During this
period, transit use fell from a post-World War II high to a low second choice
for those who could not avoid it.
Next, case-specific changes from rail to
bus service will be analyzed for cases in which data are available, with the aim
of gaining a better understanding of the impact of these changes. Finally,
changes from bus to rail service will be analyzed similarly. The results of
these analyses will speak for themselves.
PAST TRENDS
After World War II, during
1947-1975, most transit systems were modernized to take advantage of less
capital-intensive technology, expanding freeway Systems, and suburban growth by
substituting diesel buses for most electric railway services and some commuter
railroad services. Electric railway vehicles in service declined from 36,377 in
1945 to 10,712 in 1975 (7). Commuter railroad coach requirements declined
from an estimated 7,335 in 1945 to 4,438 (actual) in 1976. (An estimate had to
be made for 1945 because railroads at that time did not uniformly segregate
commuter from intercity requirements, as they now do.)
Passenger-miles traveled on shrinking
commuter railroad systems declined 7 percent, from 5.6 billion in 1945 to 5.2
billion in 1975. During this same period, suburban bus systems lost 82 percent
of their patronage, dropping from 895 million passengers in 1945 to an estimated
161 million in 1975. This loss was despite rapid growth in suburban population
and bus service offered, as well as the abandonment of 7 of the 21 commuter rail
systems (8).
Metropolitan bus services inherited many
of the transit riders left by the receding electric railways, but the number of
buses in service declined from 53,381 in 1945 to 51,514 in 1975. In Table I and
Figure 1, these trends are analyzed in 5-year increments to determine their
characteristics. During this 30-year period, transit patronage fell 69 percent,
forcing a 38 percent reduction in service. The decline in patronage was 31
percent greater than the curtailment of service, sharply reducing transit
productivity in inflationary times-the worst of both worlds.
TABLE 1 CHANGE IN
TRANSIT TRAVEL, 1945-1975
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