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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Chapter 1: Extent and Physical Condition of the U.S. Transportation System

Monday, April 4, 2016


  • The Nation’s transportation assets were valued at approximately $7.7 trillion in 2013, an increase of 13.6 percent over 2010 estimates. Publicly owned infrastructure and equipment accounted for over one-half of transportation capital stock.
  • Highway lane-miles increased slightly less than 1 percent between 2010 and 2013. Highway person-miles traveled and vehicle- miles traveled increased by 1.5 and 0.7 percent, respectively, over that period.
  • The condition of the U.S. transportation infrastructure is improving, but additional work is needed. The percentage of structurally deficient bridges dropped from 12.0 percent in 2010 to 10.5 percent in 2013.
  • One impact of bridge deterioration is reduced load limits. In 2013, 11.8 percent of all bridges had reduced load limits, which caused commercial vehicle operators to use smaller trucks or take circuitous routes, increasing their costs.
  • The average age of the highway light-duty vehicle fleet increased by 28 percent over the 2000 to 2013 period and stood at about 11.4 years in 2013. The average age of commercial trucks is now 14.7 years, up from 12.5 years in 2007.
  • The majority of airport runways (commercial service, reliever, and select general aviation) are in good condition; only 2 percent are considered poor.
  • Railroad capital expenditures totaled $13.1 billion in 2013, more than double the spending in 2000.
  • The average age of inland waterway navigation locks, adjusted for the date of the most recent rehabilitation, is more than 50 years.
  • There is a general lack of data on vehicle and traffic control system condition, regardless of mode, and on most aspects of intermodal connections.

The U.S. transportation system serves nearly 319 million Americans—including those who may not own a vehicle or rarely travel. Transportation allows us to commute to work, obtain goods and services, call on family and friends, and visit distant places. It also drives our economy, connecting 7.5 million businesses with customers, suppliers, and workers [USDOC CENSUS 2015, USDOC OTTI]. The system allows almost 75 million foreign visitors to travel to our country, resulting in a sizable contribution to the U.S. economy. The system serves a large and diverse set of users, as highlighted in appendix C and described in box 1-A.

This chapter examines both the extent and condition of the principal transportation modes, including infrastructure, vehicles and control systems, and the estimated cost of keeping or bringing the system into a state of good repair. Interconnections that link one mode with one or more other modes are also important system elements, but a lack of public data on these connections prevents meaningful analysis of their condition.

Assets and Investments

Transportation capital stock includes structures (e.g., roadways, bridges, and stations) and equipment (e.g., automobiles, aircraft, and ships). According to the Bureau of Economic Analysis, U.S. transportation capital stock was valued at an estimated $7.7 trillion in 2013, an increase of about $923 billion (13.6 percent) over 2010 estimates.1 Table 1-1 shows the estimated value of transportation capital stock increased steadily from 2000 to 2013.

Transportation assets are owned by both the public and private sectors. Freight railroad facilities and equipment are almost entirely owned by the private sector, while state and local governments own highways and bridges, airports, seaports, and transit structures. In total, publicly owned transportation accounted for over one-half of transportation capital stock; public highways and streets accounted for the largest share (42.6 percent) of this stock and much of the growth over the past few years. “Other” publicly owned transportation, such as airports, seaports, and transit structures, accounted for 8.7 percent.

In-house transportation is the largest category among the private-sector components. It accounted for 15.2 percent of transportation capital stock in 2013, most of which was highway related (e.g., truck fleets owned by grocery chains). Railroads, the next largest private sector category, accounted for 5.2 percent of U.S. transportation capital stock, followed by air with 3.0 percent. Motor vehicles owned by households and individuals, some of which are used for business purposes, accounted for 18.1 percent of capital stock.

The total value of public and private transportation construction put in place in 2014 was about $126 billion. Public transportation construction accounted for about $114 billion, or about 90 percent, of spending on transportation infrastructure [USDOC CENSUS 2014]. Approximately three-quarters of government-funded investment was for highways; the remainder supported the construction of transportation facilities and infrastructure such as airport terminals and runways, transit facilities, water transportation facilities, and pedestrian and bicycling infrastructure. In 2014 private transportation construction was about $12 billion, or about 10 percent, of spending on transportation infrastructure. Chapter 5 details transportation infrastructure spending and the revenues generated by each transportation mode.

Roads, Bridges, Vehicles, and Traffic Control Systems


Public roads, including interstate highways, other major arterials, and local routes, totaled 4.1 million miles in 2013, changing little from 2010 (as shown in box 1-A). Lane-miles increased slightly less than 1 percent over that period. Local roads are by far the most extensive, amounting to 2.8 million miles (69.2 percent of total system-miles). However, interstate highways, which accounted for about 47,600 miles (1.2 percent of total system miles), handled the highest volumes of traffic as measured by vehicle-miles traveled—24.8 percent in 2013 [USDOT FHWA 2014a]. Large Western and Midwestern states, such as Texas, California, Illinois, Kansas, and Minnesota, have the most public road mileage.2 The District of Columbia, followed by Hawaii, Delaware, Rhode Island, and Vermont, had the lowest public road and street mileage [USDOT FHWA 2014a]. Figure 1-1 shows the annual average daily traffic on the National Highway System.

The U.S. Department of Transportation’s (USDOT) Federal Highway Administration (FHWA) reports the International Roughness Index (IRI), which measures the smoothness of pavement and is a key indicator of the condition of highways and bridges.3 Box 1-B provides summary data on the percentage of rough surface mileage for different functional classes of highways. The physical deterioration of roads and bridges typically does not produce abrupt failures; rather, continued rough riding produces repetitive and gradual increases in vehicle maintenance and other highway user costs.

In urban areas the results are mixed. From 2000 to 2013, interstate highways, other expressways, and other principal arterials had 1.4 to 4.2 percent reductions in the mileage of road surfaces with an IRI above 170. In contrast, over the same period, minor arterial and collector roads showed 4.6 and 1.4 percent increases, respectively, in the mileage of roads with an IRI above 170. The overall condition of all rural roadway categories improved between 2000 and 2011, with collectors showing the greatest improvement (3.5 percent), but all rural functional classes deteriorated over the ensuing 2 years. For both urban and rural roads as the functional class decreases from interstates down to collectors the percentage of rough roads increases, and this is true over the entire time period shown. This is likely the result of road maintenance and rehabilitation programs and budgets that favor the higher throughput classes of roadway.


About 607,700 highway bridges were in use in 2013, ranging in size from rural one-lane bridges crossing creeks to urban multilane and multilevel interstate bridges. Rural local bridges accounted for about 33.4 percent of the total bridge network. By comparison, bridges in the urban and rural interstate system accounted for about 9.3 percent of all bridges in 2014, but they carried the highest volumes of motor vehicle traffic. Texas had the most bridges, accounting for 8.6 percent of the entire U.S. bridge network, followed by Ohio with 4.5 percent and Illinois with 4.4 percent [USDOT FHWA 2014b].

There has been slow but steady improvement in the condition of highway bridges, as shown in box 1-B. Two categories of bridge deficiency are tabulated: structurally deficient and functionally obsolete.

Structurally deficient bridges have reduced load bearing capacity due to the deterioration of one or more bridge elements. Such bridges are not necessarily unsafe, but they do require maintenance and repair to remain in service and will eventually require rehabilitation or replacement.

Functionally obsolete bridges, while structurally sound, often carry traffic volumes that exceed their design limits and may need to be widened or replaced. The percentages of both structurally deficient and functionally obsolete bridges declined from 2002 to 2013, with the largest declines recorded for rural bridges. Despite the improvement, 23.8 percent of urban bridges were functionally obsolete in 2013.

Figure 1-2 provides additional information on deficient bridges by age group, although age alone is not an automatic indicator of structural integrity. For example, the 132-year- old Brooklyn Bridge, due to consistent maintenance and several major rehabilitation projects, is still deemed safe for daily use, while the I-95 Mianus River Bridge in Connecticut collapsed in 1983 after only 25 years of service. The trend, however, is clear—the likelihood that a bridge will be found deficient increases with the age of the bridge. About 60 percent of deficient bridges are more than 50 years old, and one-half of bridges in place for 75 years or more are rated as deficient.

The more prevalent negative impact of bridge deterioration is the imposition of reduced load limits. In 2013 there were 71,692 bridges in the National Bridge Inventory with some type of load restriction, comprising 11.8 percent of all bridges listed [USDOT FHWA 2014b]. These load limit reductions can cause commercial vehicle operators to either use trucks with smaller payloads or take circuitous routes, both of which increase costs.


Government, businesses, private individuals, and nongovernmental organizations owned and operated about 256 million motor vehicles in 2013, up by 2.3 percent from 2010 levels (box 1-A). Motor vehicle registrations rebounded from the economic recession that began in December 2007 and continued to increase through June 2009 [NBER 2013], but remained slightly below the peak set in 2008.

Motor vehicle registrations have grown at a faster rate than licensed drivers and the population since the 1960s (figure 1-3). This growth produced an increase in the average number of motor vehicles owned by households. While U.S. vehicle registrations have changed very little since 2005, the same is not true for rapidly industrializing countries. For example, vehicle registrations in China grew from 31 million to 109 million over the 2005 to 2012 period and presently account for about 10 percent of the world total, up from 3.5 percent in 2005 [USDOE ORNL 2014].

Increases in vehicle registrations from 2010 to 2013 varied widely by vehicle type. For example, among passenger vehicles, registrations for light-duty short-wheelbase vehicles4 decreased by 3 percent, while those for light-duty long-wheelbase vehicles5 increased by 28 percent. Motorcycle registrations rose by 5 percent, continuing a long-term upward trend.

The numbers of single-unit and combination trucks registrations were down 1.1 and 3.2 percent, respectively, between 2010 and 2013. According to the U.S. Census Bureau’s 2012 Economic Census, many of these vehicles were operated by the more than 111,200 trucking establishments6 in the United States. Between the Census Bureau’s 2007 and 2012 Economic Census, a period of time that included the December 2007 through June 2009 recession, the number of trucking establishments decreased by 7.6 percent [USDOC CENSUS 2012].

The number of buses increased by 2.1 percent between 2010 and 2013. Bus registrations grew fairly steadily from 2000 to 2010 and, after a temporary dip, now stand at their highest level over the period shown. Buses owned by schools, churches, and other groups accounted for 83 percent of the registrations in 2013 [USDOT FHWA 2014a]. About 3,500 carriers operated nearly 33,000 motorcoaches (or over-the-road buses) in the United States in 2013 [ABA 2015]. The motor coach industry is discussed further in chapter 2.

There is no organized database on the operating condition of vehicles traveling on the Nation’s highways. Box 1-B shows that the average age of the light-duty vehicle fleet increased by 28 percent over the 2000 to 2013 period and stood at about 11.4 years in 2013. The commercial truck fleet is even older. The average age of the commercial trucks is now 14.7 years, up from 12.5 years in 2007 [IHS 2015].7 However, age cannot be used to gauge vehicle condition. Many older vehicles that have been well maintained continue to be in sound condition, while poorly made or maintained newer vehicles may be in poor operating condition.

Traffic Control Systems

Traffic control features, such as traffic signs, signals, and pavement markings, are an important element of the highway system, but there is no national database on traffic control systems and their condition. An estimated 311,000 traffic signals have been installed in the United States, with an aggregate public capital investment of $83 billion [NTOC 2012]. There are no comparable estimates of the numbers of other types of traffic control devices.

Public Transit

Public transit provided 10.4 billion unlinked trips in 2013, up by 1.7 billion (19.4 percent) over the 2000 total. Over 850 urban transit agencies and more than 1,700 rural and tribal government transit agencies offer a range of travel options, including commuter, transit, and trolley bus; subway and light rail; and ferryboat. Buses accounted for nearly half (about 49.2 percent) of the 137,000 transit vehicles in 2013 (box 1-A). In 2013 these transit agencies operated over 5,000 stations, 79 percent of which comply with the Americans with Disabilities Act (Pub. L. 101-336), and 1,700 maintenance facilities. Transit agencies vary widely in size, ranging from 1 to 12,500 vehicles (e.g., the New York City Metropolitan Transportation Authority) [USDOT FTA NTD 2014]. Box 1-C shows U.S. cities with bike-share systems, which often extend the reach of existing public transit systems (bus, ferry, and rail).

The average age of transit vehicles over the 2000 to 2013 period is shown in box 1-B. Commuter rail passenger coaches aged the most among rail vehicles over that period and are among the oldest of all transit equipment. The heavy-rail car fleet age decreased by 2.7 years between 2000 and 2013, but was still 20.2 years old on average. Light-rail vehicles maintained an average age of about 16 years and transit buses 8 years over the reporting period, indicating that many transit agencies retired and replaced older vehicles on a regular basis. As would be expected, the transit bus fleet remained considerably newer than the rail fleet, which has locomotives and cars that typically last for decades. The average age of ferry boats dropped by 4.2 years, but they remained the oldest part of the transit vehicle population.

There appears to be a direct relationship between public transit system condition and performance and transit ridership (see e.g., Grava 2002 for detailed discussions of the ridership history of each transit mode).

Deferred maintenance, outdated equipment and passenger stations, and numerous stops produce an overall transit image that may discourage prospective riders. Conversely, modern, well designed and maintained systems might attract riders who would otherwise travel by other means.

According to USDOT’s biennial conditions and performance report, the current total investment across all transit systems is $16.5 billion annually. Bringing all systems to a state of good repair would require an increase to $18.5 billion per year. However, increasing system capacity to accommodate higher transit ridership would require an estimated $22.0 billion to support a 1.4 percent annual ridership growth rate versus an estimated $24.5 billion to support a 2.2 percent annual ridership growth rate [USDOT FHWA and FTA 2013].


The main elements of the aviation system include airport runways and terminals, aircraft, and air traffic control systems. Box 1-A shows that in 2013 the United States had about 19,500 airports ranging from rural grass landing strips to urban rooftop heliports to large, paved, multiple-runway airports. Many commercial airports now serve aircraft that are larger than those serviced a decade ago as airlines seek to maximize profits by increasing capacity and seating more passengers. The passenger load factor—an indicator of capacity utilization— for U.S. airlines grew from 73.6 percent in 2003 to 82.7 percent in 2014 [USDOT BTS OAI 2015]. Most of the nearly 5,200 public- use facilities are general aviation airports, serving a wide range of users. In addition, there are about 14,000 private airports, which are relatively small. Figure 1-4 shows the passenger boardings at the top 50 airports in 2014. These airports account for 83.4 percent (about 597 million) of the U.S. passenger enplanements on all domestic flights in 2014 [USDOT BTS OAI 2015].

The Federal Aviation Administration (FAA) compiles data on runway pavement conditions, which are presented in box 1-B. Most airport pavements (commercial service, reliever, and select general aviation) were in good condition between 2000 and 2013, with only 2 percent rated as poor. There are no similar data for other elements of aviation infrastructure.

Box 1-B shows average ages of U.S. commercial aircraft in 2010 and 2013. The aircraft flown by the major national airlines are roughly half the age of the smaller planes used by regional airlines. There are no public data other than age to indicate the physical condition of the aircraft fleet.

The FAA is in the midst of a major effort to upgrade the U.S. air traffic control (ATC) system to increase its capacity. Current efforts are focused on developing the Next Generation Air Transportation System (NextGen), which will utilize GPS satellite technology and related communications and information technology improvements. A major reason for this effort is that the ATC system relies on ground-based radar and voice communication technologies, some of which date back to the1940s, limiting its ability to increase capacity in line with increasing air traffic demand.

The Airports Council International (ACI) surveyed its U.S. members to ascertain their capital project needs for the 2013 to 2018 period. The survey indicated a total need of $75.7 billion. Age and technological obsolescence are likely the drivers for much of this need, as many airports were built more than 40 years ago. Increasing traffic demand as the U.S. economy has improved, and airline consolidation and increased concentration on hub airports, are cited as other factors.

Large hub airports account for 53 percent of projected investment needs, while medium and small hubs make up another 22 percent. Overall, 48 percent of the funding would be for terminal improvements, and 26.5 percent would be spent on runways, taxiways, and aprons [ACI 2015].


The United States had almost 140,000 railroad route-miles in 2013 [AAR 2015], including about 95,200 miles owned and operated by the seven Class I railroads.8 Amtrak, local, and regional railroads operated the remaining 44,000 miles. Class I railroads owned and operated over 25,000 locomotives and 373,800 freight railcars.

Over the past 50 years, Class I railroads and connecting facilities have developed increasingly efficient ways to carry and transfer cargo (e.g., double-stack container railcars and on-dock rail), allowing more cargo to be carried with fewer railcars. Figure 1-5 shows that the system mileage of Class I railroads in 2013 was less than one-half the mileage in 1960. However, freight rail ton- miles nearly tripled to 1.7 trillion during the same period (despite a decline during the last recession).

Intercity Passenger Rail

The National Rail Passenger Corp. (Amtrak) is the primary operator of intercity passenger rail service in the United States. Amtrak operated 21,300 route miles in 2013 and more than 500 stations that served 46 states and Washington, DC. Figure 1-6a shows the top 25 stations by ridership across the country, and figure 1-6b shows the stations by ridership in the Northeast Corridor (NEC). Ridership was also high around Chicago as well as at several locations in California and the Pacific Northwest.

Amtrak owns a small fraction of its route miles, primarily 363 of the 456-mile NEC between Boston, MA, and Washington, DC, plus three other shorter segments totaling 261 miles [AMTRAK 2014]. The vast majority of passenger train services outside the NEC are provided over tracks owned by and shared with the Class I freight railroads. Hence, the condition of the infrastructure Amtrak uses is largely dependent on the condition of the host railroads, with the exception of the NEC.

Freight Rail

The U.S. freight rail system is privately owned and operated, and rail carriers are under no obligation to report freight track conditions to public sector agencies. Thus universal track condition reports are unavailable. Railroadsare responsible for ensuring track safety, and to that end they regularly inspect their track and perform necessary repairs. The Federal Railroad Administration (FRA) regulations require railroads to maintain track inspection records and make them available to FRA or State inspectors on request. The FRA’s rail safety audits focus on regulatory compliance and prevention and correction of track defects. Presently, there is no regular program for assembling and analyzing the many thousands of inspection reports that are prepared each year.

There is, however, one FRA program that generates systematic data on track condition. The Automated Track Inspection Program (ATIP) utilizes a small fleet of highly instrumented track geometry inspection cars to survey tens of thousands of miles of high traffic density and other high priority routes each year. Table 1-2 provides a summary of track inspection results for the years 2004 to 2014. Of the eight track inspection exceptions that are monitored, the incidences of gauge and limited speed have dropped in recent years. The FRA implemented upgrades to the inspection and collection technology in the ATIP fleet in 2013, which allowed for increased sensitivity of exception detection. Inspection locations vary by year due to the limited number of surveying cars and are prioritized by factors such as safety risk analysis and operation types.

The installation of new rail and crossties is one indicator of how track conditions are maintained and improved. The Association of American Railroads (AAR) reported that the Class I railroads installed nearly 620 thousand tons of rail and 16.2 million crossties in 2013, which is more than the annual average of 546 thousand tons of rail and 13.4 million crossties from 2001 to 2005 [AAR 2014].

The AAR also provides data on the age of the seven Class I railroad locomotive fleets (box 1-B). The fleet has become considerably newer since 2000. The percentage of locomotives that were less than 10 years old increased from 36.5 percent in 2000 to 45.2 percent in 2010, and their median age dropped from about 18 to 13 years. The pace of fleet renewal slackened a bit from 2010 to 2013 as the median age increased to about 16 years. No comparable compilation of the age distribution of railcars is available.

Box 1-B shows railroad capital expenditures, which totaled $13.1 billion in 2013, more than doubling the spending in 2000. In contrast, revenue ton-miles increased 18.7 percent over that period [AAR 2014]. Freight rail is a profit-making enterprise that self-funds its investments, and carriers have a strong incentive to maintain, rehabilitate, and upgrade their systems as needed to remain competitive in the market place and earn returns for their investors.

Ports and Waterways

More than 8,200 U.S. water transportation facilities, including cargo handling docks, handled 3.2 billion short tons of goods in 2013. Of these facilities, 2,000 handled both foreign and domestic cargo, less than 80 handled foreign cargo only, and nearly 6,100 handled domestic cargo only. About 69 percent of cargo- handling facilities are located on the coasts— Gulf coast facilities accounted for 26.2 percent of the total, followed by the Atlantic coast (21.8 percent), and the Pacific coast (20.6 percent). The remaining 31.4 percent of cargo-handling facilities are situated along the Great Lakes or inland waterways. These facilities are served by a fleet of 40,000 domestic vessels—31,000 barges and 9,000 self-propelled vessels, including almost 3,000 towboats used to move the barges [USACE IWR NDC 2015a].

Dams and navigation locks are two of the principal infrastructure features of the U.S. domestic waterway transportation system. They enable shallow draft operations on most rivers. The principal exceptions are the Lower Mississippi River and the Missouri River, which are free-flowing but still require some types of hydrologic structures, such as large rock and concrete groins and revetments, to manage the flow of the river and preserve navigation. The U.S. Army Corps of Engineers (USACE) owns and operates 239 lock chambers at 193 sites, which account for most of the U.S. inland navigation locks. The average age of all locks is over 62 years9 (box 1-B). The USACE maintains comprehensive data on lock traffic, lockage time and delay, and lock outages for waterway performance analysis.

Table 1-3 provides data on representative locks throughout the inland waterway system. These data show some of the relationships between lock age and performance factors, such as tow delay and lock chamber downtime. For example, the Emsworth Lock on the Ohio River is one of the oldest structures in the system and is considered functionally obsolete. It has lock chambers designed for vessels of an earlier era and has lengthy out-of-service delays. The newer locks on the Ohio River, such as John T. Myers, are larger and have relatively low average tow delays and only short-duration service outages. Lock 52 on the Ohio River is the busiest and also one of the oldest with chambers that are 45 and 86 years old, respectively. It had one of the highest average tow delays in the entire inland waterway system, 8.6 hours per tow in 2013.

On the Upper Mississippi River, the Melvin Price Lock has the two newest lock chambers listed in table 1-3. It passes over 40 million tons of freight per year with little delay or downtime. Just 15 miles downstream, Lock 27, with two identical size but much older chambers (61 years), has an average tow delay that exceeds 6 hours. The Inner Harbor Navigation Lock, in New Orleans, is one of the principal bottlenecks in the Gulf Intracoastal Waterway. The small chamber size of the 91-year-old lock results in an average tow delay of more than 12 hours.

Shallow and deep-draft ports and channels are other important infrastructure elements of the waterway system. There are several thousand inland river ports and terminals, the vast majority of which are privately owned and serve specific cargo-handling needs (e.g., coal loading and petrochemical transfers). Deep draft ports are large and capital-intensive facilities, typically with extensive docks, wharves, cranes, warehouses, and other cargo transfer equipment and intermodal connections that integrate ocean transport with inland connectors. Private terminal operators do not routinely release data publicly on the condition of their facilities. The USACE maintains an extensive database of marine terminals, both shallow draft and deep draft, but it is largely static and does not include condition or performance data items and summary tabulations.

Many of the coastal seaports are served by post-Panamax vessels10 that continue to increase in size. Containerships calling at U.S. ports had an average capacity of 3,542 TEU in 2013 [USDOT MARAD 2015]. Today’s largest containerships can carry upwards of 18,000 TEU. Larger vessels afford greater economies of scale and cost savings. However, they require investments in U.S. ports such as increasing bridge clearances, channel depths, landside access, and port and terminal infrastructure [USACE IWR 2012].

The main characteristic of navigation channels that relates to condition is whether the authorized depth is actually available. Nearly all channels need periodic dredging to maintain the authorized depth. Most channel dredging occurs under the auspices of the Army Corps of Engineers. In 2013 the Corps’ and contractor’s dredges removed 197 million cubic yards of material, down from 238 million in 2012. In 2013 maintenance dredging accounted for 84.3 percent of the removed material; the average cost per cubic yard increased 11.8 percent to $4.44 [USACE 2015a]. The Corps maintains detailed dredging data, but it does not produce summary tabulations that differentiate the work by deep or shallow draft channels.

U.S. flag vessels operate on both shallow and deep draft waterways and numerous foreign flag vessels call at deep draft ports. Box 1-B provides age distributions of U.S. flag vessels for the 2000 to 2013 period. The fleet got a bit younger over that period. The percent of vessels younger than 16 years increased from 34 to 46 percent. Inland waterway towboats and barges account for the largest share (85 percent) of U.S. vessels. Towboats are the oldest vessels in this assemblage; 69 percent are older than 25 years [USACE 2015]. In contrast, barges are among the youngest vessels due to a combination of retirement and replacement of older dry cargo barges and acquisition of new tank barges. This is largely in response to the Oil Pollution Act of 1990 (Pub. L. 101-380) that decreed tank barges and vessels must have double hulls by January 1, 2015.

U.S. ferries carried an estimated 103 million passengers and just over 37 million vehicles in 2009 [USDOT BTS 2014].11 Figure 1-7 shows the average number of passengers and vehicles by state. In 2009, 218 ferry operators worked in 37 states, 10 in U.S. territories and 3 between U.S. and non-U.S. locations (e.g., Canada). The U.S. ferry fleet was composed of 652 vessels, 622 of which were in active service. California had the most ferry vessels with 62, followed by New York (56), Massachusetts (52), and Washington State (46). Nearly all of the vessels carried passengers (93.4 percent), while less than half (43.6 percent) carried vehicles, and less than a quarter carried freight (22.2 percent).

While there is no definitive list of waterway transportation system investment needs, several recent studies have made estimates. Based on the fact that navigation projects account for one-third of the Corps’ 2012 budget, the American Association of State Highway and Transportation Officials (AASHTO) estimated the agency’s navigation project backlog totaled$20 billion [AASHTO 2013].


Natural gas was transported via about 320,000 miles of natural gas transmission pipeline and over 2.1 million miles of natural gas distribution main and service pipelines in 2013 (box 1-A). These pipelines connect to 65 million households and 5 million commercial businesses, and to the 1,900 electrical generating units that supply approximately 25 percent of U.S. electricity [AGA 2015]. Over 192,000 miles of crude/refined oil and hazardous liquid pipelines carried over 2.2 billion barrels across the United States [USDOE EIA 2015b].

The Pipeline and Hazardous Materials Safety Administration (PHMSA) collects annual report data from pipeline operators, covering their system mileage, commodities transported, and inspection activities, but there is no publicly available database that tracks pipeline condition. A serious failure, such as the Santa Barbara, CA, crude petroleum pipeline failure in May 2014, serves as a reminder that this part of the transportation system has the same problems with aging infrastructure as the other modes profiled in this chapter [USDOT PHMSA 2015].

As with railroads, pipeline companies are private enterprises that are responsible for their own system maintenance, rehabilitation, and expansion. Hence, there are little data or estimates available on systemwide capital investments.


With the largest transportation system in the world, the United States faces a continuing challenge of maintaining system conditions in sufficiently good shape to meet the enormous mobility requirements of the American economy and society. As indicated earlier, the condition of transportation infrastructure is improving, but additional improvements are needed. The average age of all inland waterway navigation locks is more than 50 years, and 11 percent of highway bridges are considered structurally deficient. If these condition issues are not addressed, they could affect system performance in the coming years.


Airports Council International (ACI). Airport Capital Development Needs 2015-2019 (March 2015). Washington, DC. Available at as of July 2015.

American Association of State Highway and Transportation Officials (AASHTO). Waterborne Freight Transportation Bottom Line Report, June 2013. Washington, DC.

American Bus Association (ABA) Foundation. Motorcoach Census 2013 (March 2015). Available at as of March 2015.

American Gas Association (AGA). Facts About Natural Gas (2015). Available at as of June 2015.

Association of American Railroads (AAR), Railroad Facts (2014), Available at as of June 2015.

Grava, S. Urban Transportation Systems (2002). McGraw-Hill, New York, NY.

IHS Automotive (IHS). As quoted in Fleet Owner (Nov. 7, 2014). Available at, as of June 2015.

National Bureau of Economic Research (NBER). U.S. Business Cycle Expansions and Contractions. Available at as of July 2013.

National Railroad Passenger Corporation (AMTRAK). National Fact Sheet: FY 2013 (2014). Available at as of July 2014.

National Transportation Operations Coalition (NTOC). 2012 National Traffic Signal Report Card Technical Report. Institute of Transportation Engineers, Washington, DC. Available at as of June 2015.

Transportation Research Board (TRB). Funding and Managing the U.S. Inland Waterways System: What Policy Makers Need to Know, Special Report 315, 2015. The National Academies, Washington, DC. Available at as of August 2015.

U.S. Army Corps of Engineers (USACE). Institute for Water Resources (IWR). Navigation Data Center (NDC):

—2015a. The U.S. Waterway System. Transportation Facts and Information (January 2015). Available at as of June 2015.

—2015b. U.S. Waterborne Container Traffic by Port/Waterway in 2013 (March 2015). Available at http://www.navigationdatacenter. us/ as of June 2015.

U.S. Army Corps of Engineers (USACE). Institute for Water Resources (IWR). U.S. Port and Inland Waterways Modernization Preparing for Post-Panamax Vessels (June 2012). Available at as of September 2013.

U.S. Central Intelligence Agency (USCIA). The World Factbook: United States. Available at as of June 2015.

U.S. Department of Commerce (USDOC), Census Bureau (CENSUS). Value of Construction Put in Place, Not Seasonally Adjusted (2002-2014), available at as of April 2015.

U.S. Department of Commerce (USDOC). Census Bureau (CENSUS). American Fact Finder (2015). Available at as of June 2015.

U.S. Department of Energy (USDOE). Energy Information Administration (EIA). Crude Oil and Petroleum Products Movements by Pipeline (May 2015). Available at as of June 2015.U.S. Department of Energy (USDOE), Oak Ridge National Laboratory (ORNL), Transportation Energy Data Book. 33rd edition. Available at as of July 2014.

U.S. Department of Transportation (USDOT). Bureau of Transportation Statistics (BTS):

—2015. Office of Airline Information (OAI). Airlines and Airports. Available at as of June 2015.

—2014. National Census of Ferry Operators (NCFO). Available at as of June 2014.

U.S. Department of Transportation (USDOT). Federal Highway Administration (FHWA):

—2014a. 2013 Highway Statistics. Available at as of December 2014.

—2014b. Bridges & Structures. Available at as of November 2014.

U.S. Department of Transportation (USDOT), Federal Highway Administration (FHWA) and Federal Transit Administration (FTA). 2013 Status of the Nation’s Highways, Bridges, and Transit: Report to Congress (Washington, DC). Available at as of November 2013.

U.S. Department of Transportation (USDOT). Federal Transit Administration (FTA). National Transit Database (NTD). 2013 Data Tables. Available at as of January 2015.

U.S. Department of Transportation (USDOT). Maritime Administration (MARAD): 2013 Vessel Calls in U.S. Ports and Terminals, June 2015. Available at, as of June 2015.

U.S. Department of Transportation (USDOT), Pipeline and Hazardous Materials Safety Administration (PHMSA). Serious Pipeline Incidents (2015). Available at, as of June 2015.

U.S. Department of Transportation (USDOT). Surface Transportation Board (STB). Railroad Revenue Thresholds (2013). Available at as of June 2014.


1 Subtracted out from the reported totals are the amount of depreciation of aging equipment and structures and the value of assets taken out of service.

2 Alaska, the largest state by land area, has relatively few miles of roads, which reflects the lightly populated and relatively undeveloped character of the large landmass that lies outside of the Anchorage to Fairbanks corridor.

3 A highway that has a roughness rating greater than 170 inches per mile is considered in poor condition.

4 Light duty vehicle, short wheel base includes passenger cars, light trucks, vans, and sport utility vehicles with a wheelbase equal to or less than 121 inches.

5 Light duty vehicle, long wheel base includes large passenger cars, vans, pickup trucks, and sport/utility vehicles with wheelbases larger than 121 inches.

6 There are over 500,000 interstate freight carriers reg- istered with the U.S. DOT, which includes many private carriers operated by firms whose primary business clas- sification is not transportation.

7 IHS Automotive acquired R.L. Polk & Co. in 2013 and continues the former Polk automotive registrations proprietary data series.

8 Includes BNSF Railway, CSX Transportation, Grand Trunk Corp., Kansas City Southern, Norfolk Southern, Soo Line (Canadian Pacific operations in the United States), and Union Pacific.

9 A recent Transportation Research Board (TRB) report [TRB 2015] shows that, when adjusted for the dates of major rehabilitation projects, the effective average age of locks is about 10 years less, but that still puts the average age at over 50 years.

10 Vessels exceeding the length and width of the lock chambers in the Panama Canal. The Canal expansion project is scheduled to be completed in 2016, so vessels that exceed its new larger lock chamber size are referred to as ”new Panamax.”

11 These data will be updated in the 2014 National Cen- sus of Ferry Operators, which is undergoing imputation.