TR Circular E-C058_9th LRT Conference_2003.pdf - Florida ...

362 Transportation Research Circular E-C058: 9th National Light Rail Transit Conference
service levels at or near practical (site-specific) maxima. This suggests that, at least in some
cities and corridors, unserved demand does still exist. Examples include
• Portland: A September 1998 service increase was followed by a large ridership
increase. Weekday vehicle-trips were increased by 31%, from 388 to 510. Weekday services
(train-trips) were increased by 19%, from 213 to 255. Eastside Line ridership at October 1998
was 37,200 passengers per weekday (p/w), up by 34% from the October 1996 level of 27,700
p/w. An expanded vehicle fleet permitted a peak-period service increase from 17 to 22 vhd, or
29%. This was accompanied by a 17.5% peak-hour ridership increase, from 2,100 to 2,500 phd.
The majority of the weekday ridership growth occurred outside of the peak-period, peakdirection
travel market. This may reflect “reverse direction” travel by passengers riding through
from the new Westside Line, which opened in September 1998, to employment centers east of
the CBD.
• Los Angeles: University of Southern California researchers counted 24,100 boardings
in June 1991. Two months later, the operator counted 32,587 boardings. Moore (18) labels the
latter an “outlier” and implicitly questions its veracity. However, peak service frequency was
increased from 10 min to 7.5 min prior to the second count. A 33% service-supply increase,
during the hours when roughly 50% of weekday transit ridership occurs in the United States, is a
very significant change and corresponds well to the 35% increase in reported boardings. The
explanation offered by Moore (18), reduction of parallel bus service, was much too small to
account for this. 6
Peak Service Supply and Peak Vehicle Occupancy: Theory Versus Practice
Previous modal comparisons and planning studies often assumed different, usually higher,
service-supply and vehicle-occupancy levels from those observed in actual operation. Results are
therefore biased in a manner that does not reflect actual experience.
Observed PVO in most metropolitan areas is much less than vehicle capacity usually
assumed by planners. This comes as no surprise. Transit vehicle capacity ratings typically reflect
arbitrary standards of floor space per passenger, and are highly inconsistent between operators.
The authors have not found any cases where loading standards were based on the wishes of
consumers, demonstrated consumer choice, or feedback from surveys of potential passengers or
focus groups.
Observed PVO reflects a complex relationship among several demand and supply factors.
It is also an important indicator of consumer choice, and reflects willingness to travel as a
standing passenger and willingness to tolerate existing levels of crowding aboard transit vehicles
(whether standing or seated). Ancillary effects of high crowding levels also influence this choice:
increased loading and unloading (dwell) times, irregular intervals between vehicles and lack of
space onboard. PVO levels off at the point where, on average, prospective passengers choose to
travel at a different time or by a different mode.
It is now clear that U.S. and Canadian consumers will not accept the PVO standards used
for many planning studies during the 1970s and 1980s. This is demonstrated by the stabilization
of observed PVO at similar levels in corridors having a wide range of demand characteristics
(Table 1–3). In Portland, operator staff members have concluded that Portland transit passengers
will not accept LRT vehicle occupancies greater than 135 p/v (4.9 p/m), except for special
events. Prior to construction, LRT planners estimated the capacity of each 90-ft vehicle at 166