Part I: Description of Current System
Part II: Investment Performance Analyses
Part III: Bridges
Part IV: Special Topics
Part V: Supplemental Analyses of System Components
Ch 9: Impacts of Investment
Linkage Between Recent Condition and Performance Trends
and Recent Spending Trends
Spending by all levels of government on system preservation increased by 45.7 percent from $23.0 to $33.6 billion between 1997 and 2000. This increased investment in roadway and bridge rehabilitation and resurfacing is reflected in the improvements in pavement ride quality and reductions in bridge deficiencies that are described elsewhere in this report.
Investment in system expansion has also increased, but at a much lower rate
relative to outlays for system preservation. While the rate of growth in
average annual hours of traveler delay has decreased, the level of investment
has not stopped the overall growth in congestion.
Impact of Future Investment on Highway Conditions and Performance
If average annual highway capital investment from 2001 to 2020 reaches
the projected $106.9 billion Cost to Improve Highways and Bridges
level and is applied in the manner suggested by the analysis, the average
pavement quality is projected to improve by 13.9 percent relative to year
2000 levels. Improvements in highway operational performance would cause
average speeds to rise by 6.0 percent, while average highway user costs
would decline by 3.6 percent.
If all levels of government combined invested at the Cost To Maintain
projected level of $75.9 billion, and shifted more of their investment toward
system expansion to address increasing congestion problems, average speeds
would improve, while average pavement roughness would worsen. By definition,
user costs would remain at year 2000 levels.
Impact of Investment on Travel Growth
While future travel growth will be primarily driven by factors such as population
growth and growth in economic activity, the amount of travel growth on a
highway segment may also be affected by the level of investment on that
segment. Investments that reduce the economic cost of using a facility may
lead to increased use, while increasing congestion on an unimproved roadway
may cause travel growth to be lower than it otherwise would be. The travel
growth forecasts used in the analysis of highway investment requirements
in this report are dynamic, in the sense that they allow feedback
between the level of future investment and future VMT growth.
If highway-user costs are maintained at current levels as they would be
under the Cost to Maintain scenario, the analysis projects that urban VMT
would grow by an average annual rate of 1.96 percent. If highway-user costs
declined, as they would under the Cost to Improve scenario, this rate would
increase to 2.19 percent per year.
The Transit Economic Requirements Model (TERM) does not estimate the
impact of capital investment in transit infrastructure on the demand for
transit services. Rather, assumed growth in passenger miles traveled (PMT)
is the driving factor in estimating transit investment needs. For
this reason, it is impossible to determine how achieving the required
investment levels would affect transit ridership, user costs, and the
potential for additional capital investment. There is evidence, however,
to suggest that investments in transit infrastructure in areas with latent
transit demand will increase ridership.
Historically and since 1993, actual investment in transit capital infrastructure has been less than estimated investment requirements to Maintain Conditions and Performance.
Changes in Condition and Age
As indicated in Chapter 3, the average condition of bus vehicles
has been relatively constant over the last 13 years, with a very slight
improvement in 1993. The average condition of rail vehicles, on the
other hand, appears to be gradually declining-from 3.91 in 1987 to 3.55
in 2000. The average age of bus vehicles, including vans, gradually
declined during the early nineties but has remained relatively constant
(at about 7 years) since 1996. The average age of the rail fleet has increased
from 15.6 years in 1987 to 20.4 years in 1997, and 21.8 years in 2000. As
fleet size has increased since 1987, the absolute number of overage vehicles-both
bus and rail-has also increased. In 2000, there were 16,000 overage buses,
44 percent more than in 1987, and 6,770 overage rail vehicles, 138 percent
more than in 1987. Although the conditions of non-vehicle
infrastructure appear to have improved since 1997, a significant percentage of these assets are in less than adequate condition.
Changes in Performance
In 2000, the average rail speed was 24.9 miles per hour, its lowest
rate since 1990, and rail vehicle utilization rates reached new highs
in 2000, well above the utilization rates that existed in the early 1990s.
This reflects increased usage in the larger, older systems, which tend to
have slower speeds.
Historical Capital Investment and Conditions and Performance
Capital spending levels have been approximately equal to or slightly
higher than the pure replacement and rehabilitation levels necessary to
Maintain Conditions. However, about half of current capital spending
appears to have been allocated to rehabilitation and replacement, with the
remainder going to asset expansion. Although past spending levels appear
to have Maintained Conditions for buses and to have almost Maintained Conditions
for rail vehicles, the absolute number of overage bus and rail vehicles
has increased. During the past few years, funding levels have been sufficient
to Maintain Performance for bus modes of public transport, but the performance
of rail modes has declined slightly.