Surface Transportation Research and Technology Assessment
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1. Surface Transportation System Baseline
Condition and Performance
The well being and vitality of the surface transportation infrastructure are essential
to the safety, mobility, and economic prosperity of the Nation. In direct expenditures
alone, transportation-related activities account for about 11 percent of the U.S. Gross
Domestic Product. The underpinnings for these activities, transportation infrastructure
systems, must be restored, renewed, preserved, and strengthened on a regular basis while
they continue to serve the ever-growing and changing transportation needs of our Nation.
To assess the role that technological innovations could play in making stewardship of the
surface infrastructure system more efficient and cost-effective, potential applications of
new technology must be evaluated against a system condition and performance baseline. This
chapter reviews the condition and performance issues related to surface transportation
infrastructure maintenance and renewal specific to roads, railroads, and transit, and the
related links to airports and ports and waterways. Although the focus of this report is a
systems look at surface transportation R&T programs, transportation statistics and
research agendas are developed, managed, and published modally. Therefore, modal
descriptions and information are necessary, with a return to a systems perspective as
appropriate and useful.
Roads and Bridges
According to the FHWA, the average condition of pavement continues to improve. However,
more than six percent of all pavement is in need of immediate repair; an additional
thirteen percent will require attention within five years to avoid being rated in poor
condition. (See Figure 2)
While the condition of the nation's bridges also continues to improve, approximately 27
percent, or about 93,000, bridges are classified as deficient. Functional deficiencies,
such as being too narrow, are slightly more prevalent than structural deficiencies, such
as design load limitations. (See Figure 3)
The Federal Highway Administration estimates that maintaining current physical
conditions on existing roadways and bridges without raising costs to the users of the
system would require an investment of about $29 billion annually: $23.5 billion for
highways and $5.6 billion for bridges. Capacity-related improvements to keep congestion
near current levels call for another $17 billion annually. 2
In 1995, only about $17.5 billion of the $35 billion in total capital expenditures on public roadway infrastructure (excluding local roads and streets) went toward preserving or upgrading existing
facilities to meet current design standards. Of the remainder, $8.9 billion in capital
investment was directed toward improved capacity, $5.4 billion was invested in new roads
and bridges, and $3.2 billion was invested in other improvements such as safety features,
traffic control systems, and noise barriers.3 In addition
to capital investments, $44.8 billion was spent on non-capital expenditures, including $24.5 billion for maintenance. 4
Figure 2. Pavement Condition of U.S. Highways
Source: U.S. Department of Transportation,
1997 Condition and Performance, p. 26.
Figure 3. Deficient Bridges in the National Inventory (1996)
Source: U.S. Department of Transportation,
1997 Condition and Performance, pp. 28-29.
As encouraged by the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991,
states and localities have increased the emphasis on system preservation, maintenance, and
operations. In constant dollars, spending for highway maintenance and operations
(including research and administration) grew at twice the rate of total highway spending
from 1960 to 1993. This trend is expected to continue as the massive highway construction
associated with building the Interstate Highway System draws to a close. However, highway
infrastructure needs are expected to grow over the coming decade, with both freight and
passenger travel continuing to climb. Figure 4 shows the growth trend in U.S. freight
tonnage for railroads and trucks, and the total for all modes.
Figure 4. Freight Tonnage Rail, Truck, and Total
Source: The Eno Transportation Foundation, Inc.,
Transportation in America:
Historical Compendium, 1939-1995, 1997, p. 19.
As traffic on the Nation’s network of roads and streets increases, the most
heavily traveled segments become overloaded, severely degrading operational performance.
Since 1985, traffic on urban Interstate highways has grown steadily at an average rate of
2.4 percent per year. The result is that congestion within segments of the highway network
is increasing. Between 1990 and 1995, the portion of peak-hour urban Interstate highway
travel occurring under congested conditions rose from about 50 percent (1990-92) to about
52 percent (1993-95). Congested roadways indicate the need for technologies and techniques
to monitor infrastructure condition and determine remaining service life, and for rapid
reconstruction and renewal processes that minimize their contribution to congestion.
Transit
The U.S. transit system consists of 537 public transit operators in 316 urbanized
areas. 7 Urban mass transit use is concentrated in
large cities with both bus and rail service, including metropolitan New York City (the largest single mass transit market), Los Angeles, San Francisco, Chicago, Washington DC, Philadelphia, and Boston. In 1995, the
national transit system included the following:
- 43,577 buses with 17.0 billion passenger-miles;
- 8,725 rapid rail and light rail vehicles with 11.4 billion passenger-miles;
- 4,413 commuter rail vehicles with 8.2 billion passenger-miles;
- 68 ferries with 243 million passenger-miles; and
- 12,825 demand response vehicles with 397 million passenger-miles. 8
Local governments dominate the operation and maintenance of public transit systems, as
well as funding some construction, but state governments are playing an increasing role in
transit system support. Federal outlays by the FTA include grants to States and local
agencies for the construction, acquisition, and improvement of mass transportation
facilities and equipment, and for the payment of operating expenses. The FTA Grants
Program provides funding to transit agencies for both buses and infrastructure. States can
also draw on Congestion Mitigation and Air Quality (CMAQ) funding for environment-related
improvements, as well as other Surface Transportation program (STP) flexible funds for
certain transit activities. Since 1988, FTA has provided capital grants to transit
agencies for purchase of over 2,000 alternative-fuel buses operating on ethanol, methanol,
liquefied gas, and compressed natural gas. In addition, FTA provides research funding.
Other current infrastructure improvements are driven by the need to meet requirements
mandated by the Americans with Disabilities Act, such as the upgrade or installation of
gates, signage, and station monitors. Some funding also is directed towards the physical
security of transportation facilities and their patrons.
In addition, investments are being made with Federal assistance in modernizing older
facilities. Even the relatively new systems, such as the Washington (DC) Metro system and
the Bay Area Rapid Transit system (BART), are approximately twenty years old. As these
systems age, they require increasingly large maintenance programs to maintain an
acceptable reliability and safety level. Federal aid targeting system modernization and
renewal has paid off in improved infrastructure conditions. For transit and commuter rail
infrastructure, the condition of power stations, systems, bridges and tunnels, and
maintenance improved between 1984 and 1995. In 1995, 73 percent of elevated structures
were judged to be fair to good condition, and 73 percent of track and 61 percent of
stations were in good to excellent condition. 9
A survey of urban bus maintenance facilities in 1995 found that 74 percent were in good or excellent condition, also a significant improvement over previous assessments. However, all these structures will need continued investments to sustain acceptable performance.
Railroads10
The U.S. railroad industry has been transformed significantly since the enactment of
the Staggers Rail Act of 1980. The changes that have occurred in the railroad industry
over the past two decades (and continue still) have been as radical as any that have taken
place during the industry’s 175-year history. By gaining the flexibility to negotiate
rates and choose routes, the industry has been able to respond more effectively to market
demands. The outcome has been the emergence of a small number of larger, more profitable
carriers carrying more freight tonnage and passengers, as well as providing more
freight-miles and passenger-miles. This has been accomplished with fewer employees,
terminals, track miles, railcars, and locomotives. Revenues for Class I railroads in 1995
totaled $32.3 billion, and they carried a total of 1.7 billion ton miles of cargo. This is
an increase 42 percent from 1980. Profitability was at an all-time high.
In 1995, the nation’s railroad infrastructure consisted of about 170,000 miles of
track owned and maintained by freight railroads and Amtrak. Figure 5 shows the locations
of major intermodal rail and maritime terminals having significant annual lift capacity or
container throughput. Activities at these terminals have major impacts on other surface
transport infrastructure connecting links.
The average tonnage hauled per train also has increased from 2,144 tons in 1980 to
2,849 tons in 1995. This trend has affected the need for track maintenance, for which
industry expenditures have been rising moderately over the past ten years. In 1995, Class
I railroads spent $3.3 billion on track maintenance, representing 12 percent of their
total operating expenditures.
Figure 5. Major Intermodal Rail and Maritime Terminals
Amtrak is the nation’s only intercity passenger railroad. With the exception of a
few high-density corridors (particularly in the northeastern United States, Los Angeles,
and Chicago), freight railroads own the tracks and infrastructure used by Amtrak and
commuter railroads. Amtrak carried 20.7 million passengers and produced 5.5 billion
passenger miles on intercity routes in 1995, for revenues of $1.5 billion. Amtrak operates
many of the Nation’s commuter railroad services for transit agencies. Commuter rail
traffic has been the most rapidly growing segment of the railroad industry, with the
number of passenger trips increasing by 27 percent over the past ten years.
Railroad and grade crossing fatalities declined significantly from 1960 through 1995,
with fatalities down by nearly 40 percent and grade crossing accidents down by nearly 60
percent. Human factors and track defects are considered to be the most significant causes
of these accidents; 35 percent of accidents are attributable to human factors, while track
defects account for 34 percent of the accidents. Equipment defects and other factors are
responsible for the remainder.
The last ten years have brought increases in infrastructure investment, steady growth
in international trade, and mounting demand for timely delivery of freight. These trends
have forced changes in railroad operating characteristics that may affect the durability
of the existing track structure, including the following:
- Higheraxle loads, resulting from increases in the average gross weight per train due to changes in load types and new double-stack cars for hauling containers;
- Increased traffic density, due to growing domestic trade and intermodal freight demand;
- Higher locomotive speeds, to meet demands imposed by competitive pressures and just-in-time requirements;
- Aging, because the risk of track defects relating to bridge failure or material degradation increases as the infrastructure ages; and
- Reduced maintenance labor capacity - as one indicator of maintenance labor capacity, the number of maintenance workers per track mile, has been declining steadily. 11
Ports and Waterways
Ports are big business. The nation’s maritime facilities include 26,000 miles of
navigable inland rivers and intra-coastal waterways, and 3,740 port facilities. In 1995, a
total of 1.1 billion tons of domestic freight was transported through the U.S. waterways.
Roughly 60 percent of the domestic waterborne trade moved on inland rivers and canals, 30
percent on coastal waterways; and another 10 percent on the Great Lakes. The value of
waterborne international exports and imports traded in international commerce in 1995
totaled $620.4 billion, with the greatest concentration at the ports of Long Beach, Los
Angeles, and New York/New Jersey. All goods move to ports by surface transportation; thus,
improvements in ports and waterways inevitably create more landside traffic, affecting
already congested highways and freight rail connections.
Indeed, at the most active ports, demand for railroad and roadway access currently is
increasing due to growing container movements, larger vessels, and bigger trucks.
Container throughput, which measures the capacity of the marine infrastructure, has risen
by nearly 200 percent over the past fifteen years in the continental United States, from
approximately six million 20-foot equivalent unit (TEUs) in 1980 to just under 17.7
million TEUs in 1995. Also in recent years, container vessels have increased in size from
3,900 TEU containers to more than 5,000 TEUs, and "megaships" of greater than
6,000 TEUs are being deployed in world trade. Corresponding increases in truck volume,
axle size, weight, and turning radius requirements to move these heavier containers
already are placing heavier demands on highways at seaports.
In addition, pavement and bridge damage from excessive container weight can be
significant. A survey conducted several years ago indicated that approximately 40 percent
of the exported containers and 25 percent of the imported containers moving through U.S.
ports exceeded the FHWA limits for their respective container/chassis weight. Many ports
are reluctant to enforce highway weight limits, fearing a loss of shipping business in
this highly competitive industry.
Finally, responsibility for managing ports and waterways and performing maintenance and
monitoring functions is shared by Federal, state, local, and private entities. Federal
agencies involved in marine transportation include the U.S. Coast Guard, U.S. Army Corps
of Engineers, National Oceanic and Atmospheric Administration (NOAA), Environmental
Protection Agency (EPA), Department of Defense (DOD), and MARAD. Environmental
considerations, including wetlands protection and coastal land use regulations, limit the
ability of many ports to provide additional landside access.
Airports
The United States has over 5,400 public use airports providing the Nation with the
infrastructure and services necessary for successful operation of the world's largest
aviation system. In 1995, the air transportation system accommodated 5,567 passenger
aircraft that flew a collective total of over 4.6 billion miles. Flying in those aircraft
were more than 548 million enplaned passengers. In addition, 12.5 billion domestic
ton-miles of freight were transported by air in 1995. 13
Airport runways, taxiways, and aprons are discussed in this report, because the results
of aviation-related pavement R&T programs are applicable to surface transportation
infrastructure in other modes. The total investment in airport surface infrastructure
currently exceeds $100 billion. In several respects, runway performance and condition are
as critical to safe airport operations as air traffic control. First, runway operations
can minimize the risks associated with weather. From 1980 to 1991, 130 aircraft accidents
were directly attributed to runway overruns and veer-offs resulting from snow, ice, water,
and rubber deposits on runways. In addition, pavement outages and downtime for maintenance
and rehabilitation contribute to the costs associated with aviation system delays. Many
research and technology efforts are directed toward reducing the impact of runway
maintenance and other pavement outages on airport traffic operations, thereby reducing
overall aviation system delays. In addition, the FAA airport research and technology
program is seeking to improve runway traction and safety characteristics
To accommodate the next decade of anticipated strong growth in global aviation, the
Federal government continues to make substantial investments in airport infrastructure,
including airport pavements. In 1994, FAA planners approved some 1,500 applications for
airport runway projects to preserve, improve, and expand the over 650 million square yards
of airport runway pavement. For the past several years, annual funding for airport surface
infrastructure activities has been approximately $2 billion, with most of this funding
directed toward the 67 largest airports. 14
Summary
Federal funding and resources devoted to highway maintenance and operations by States
and localities have increased to all-time highs, and the recent Transportation Equity Act
for the 21st Century (TEA 21) of 1998 authorizes continued historic levels of
spending. Despite these increases, however, there is room for improvement. Transit
agencies face the dual challenge of renewing the oldest systems such as New York and
Boston, and the simultaneous maturing of newer systems, like those in San Francisco and
Washington DC. Commuter rail passenger growth has required expansion and modernization for
many systems. Although progress has been made in reversing deterioration for the older
facilities, continued renewal and some major reconstruction will be necessary over the
coming decades for every transit system’s infrastructure.
The Nation’s port and railroad infrastructures also must modernize and renew while
coping with increasing demand. The number of intermodal container movements is growing. In
addition, there are significant increases in the size and configuration of the ships and
trains carrying the containers and the trucks moving the containers to their final
destinations. This creates more demand for landside access and intermodal facilities,
particularly at the most active ports. The responsibility for maintaining and managing the
maritime infrastructure is spread among multiple public and private sector entities. This
greatly complicates making decisions about large infrastructure and surface access project
financing and implementation.
Technology can and should play a pivotal role in meeting the demands for maintaining
infrastructure in good working condition, providing better service, and keeping
preservation and life-cycle costs as low as possible. However, for technology to be
effective, the rate of adoption by those responsible for project implementation must
accelerate. The following chapters identify key technologies and point to promising
avenues leading in the direction of realizing their capabilities.
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