INTERMODAL 

TRANSPORTATION

A Variety of Factors 

Influence AirportIntercity Passenger 

Rail Connectivity 

Report to Congressional Committees

August 2013

GAO-13-691

United States Government Accountability Office
United States Government Accountability Office

Highlights of GAO-13-691, a report to 

congressional committees

August 2013

INTERMODAL TRANSPORTATION

A Variety of Factors Influence Airport-Intercity 

Passenger Rail Connectivity

Why GAO Did This Study

Increasing passenger travel has led to 

growing congestion in the nation’s air 

transportation system, and projections 

suggest that this trend is likely to 

continue. The integration of air and 

intercity passenger rail service, which 

is provided in the United States by 

Amtrak, has been suggested by some 

transportation experts as a strategy to 

increase mobility and reduce 

congestion in the United States. The 

FAA Modernization and Reform Act of 

2012 mandated that GAO review 

issues related to air-rail connectivity. 

This report discusses (1) the nature 

and scope of air-rail connectivity, (2) 

the benefits and costs of air-rail

connectivity, (3) factors affecting the 

development and use of air-rail 

connectivity, and (4) potential 

strategies to improve air-rail 

connectivity. 

GAO reviewed laws, strategic plans, 

and academic studies. GAO analyzed 

data to determine distances between 

Amtrak stations and large and medium 

hub airports and interviewed officials 

from DOT, and representatives from 

Amtrak, the airlines, and aviation and 

rail industry associations. GAO 

interviewed stakeholders at eight large 

and medium hub airports, which were 

selected based on geographic location 

and extent of connectivity with Amtrak. 

In addition, GAO surveyed experts 

from the aviation industry, rail industry, 

state and local governments, academia 

and the private sector about air-rail 

connectivity issues. The survey and 

results can be found at GAO-13-

692SP. 

GAO is not making recommendations 

in this report. DOT and Amtrak 

provided technical comments, which 

were incorporated as appropriate.

What GAO Found

Most major U.S. airports have some degree of physical proximity to intercity 

passenger rail stations, though only 2 airports are currently collocated with

intercity rail stations. Specifically, 42 of the nation’s 60 large and medium hub 

airports are located within 10 miles of Amtrak stations; 21 of the 42 airports are

within 5 miles of Amtrak stations. At the 2 collocated airports, passengers can 

access Amtrak either via an automated people mover (Newark Liberty 

International Airport) or by walking (Bob Hope Burbank Airport). At some airports, 

such as Baltimore/Washington International Thurgood Marshall Airport, 

passengers can take a direct shuttle between the airport and the nearby Amtrak 

station, while at other airports, connections to Amtrak can be made through other 

modes of transportation. Studies and data, while limited, suggest that relatively 

few passengers in the United States use intercity rail to travel to and from the 

airport or through more integrated travel such as code-sharing agreements, 

whereby airlines sell tickets for Amtrak’s service. The only existing air-rail codesharing agreement in the United States is at Newark Airport. Amtrak and states 

are considering projects to expand intercity rail connectivity with airports, 

including as part of the construction of high-speed rail in California. 

Air-rail connectivity may provide a range of mobility, economic, and 

environmental benefits, though the financial costs of building these connections 

could be substantial. Specifically, based on discussions with industry 

stakeholders, input from surveyed experts, and a review of academic literature,

GAO found a general consensus that air-rail connectivity can provide a range of 

mobility benefits for travelers, though less agreement existed on the importance 

and extent of economic and environmental benefits. However, achieving these 

benefits could require significant trade-offs, because the costs of expanding the 

existing intercity passenger rail network and constructing viable connections can 

be significant. Given these costs, based on GAO’s work, there are currently 

limited locations where benefits are high enough to justify funding to improve airrail connectivity.

Air-rail connectivity remains limited in the United States, according to experts, as 

a result of institutional and financial factors, among other things. In particular, the 

limited nature of the existing intercity passenger rail network, including the 

frequency of service and connectivity to other transportation modes, remains an

obstacle to developing and using air-rail connections. Securing funding for air-rail

projects also remains a barrier. While funds from some federal grant programs 

can be used to help facilitate air-rail connections, there is no single funding 

source for air-rail projects.

There are strategies to improve air-rail connectivity, but adopting them involves

trade-offs. Experts generally focused on, among other things, leadership, 

funding, and infrastructure improvements, though the effectiveness of these 

strategies may depend on a project’s local characteristics. There has been little 

emphasis on air-rail connectivity by either the Department of Transportation 

(DOT) or Amtrak. Furthermore, experts noted that some of the strategies could

be particularly challenging or costly to implement, such as in locations where the 

rail network was developed decades before airports. For example, increasing 

intercity passenger rail’s frequency could improve air-rail connectivity but could 

also be expensive.

View GAO-13-691. For more information, 

contact Gerald Dillingham at (202) 512-2684 

or dillinghamg@gao.gov.
Page i GAO-13-691 Intermodal Transportation

Letter 1

Background 4

Connectivity between Major Airports and Intercity Passenger Rail 

Remains Limited, as Does Passenger Usage 11

Air-Rail Connectivity May Provide a Range of Benefits for 

Passengers and Others, but Costs Can Be Significant 16

Air-Rail Connectivity Is Influenced by a Variety of Factors 25

Strategies to Improve Air-Rail Connectivity May Require 

Substantial Coordination and Funding 30

Agency Comments 36

Appendix I Objectives, Scope, and Methodology 38

Appendix II Experts Participating in GAO’s Survey on Air-Rail 

Connectivity 43

Appendix III Examples of Potential Federal Financing and Funding 

Sources for Air-Rail Projects 45

Appendix IV Distances between Large and Medium Hub Airport Terminals 

and Amtrak Stations in the Contiguous United States 47

Appendix V GAO Contact and Staff Acknowledgments 49

Tables

Table 1: Benefits of Air-Rail Connectivity Most Frequently Cited as 

“Very Important” by Experts Surveyed 17

Table 2: Projected Construction Costs of Selected On-Going 

Projects to Expand Air-Rail Connectivity 22

Table 3: Factors Surveyed Experts Most Frequently Cited As 

Greatly Facilitating and Greatly Hindering Air-Rail 

Connectivity 25

Contents
Page ii GAO-13-691 Intermodal Transportation

Table 4: Experts’ Rating of Importance and Feasibility of Selected 

Strategies to Improve Air-Rail Connectivity 30

Table 5: Airports and Stakeholders Selected for GAO Review 39

Figures

Figure 1: Large and Medium Hub Airports within 10 Miles of an 

Amtrak Station, May 2013 12

Figure 2: Construction of the Miami International Airport Miami 

Central Station, February 2013 18

Figure 3: Signage and Information at the BWI Airport Amtrak 

Station 36

Abbreviations

AIP Airport Improvement Program

Amtrak National Railroad Passenger Corporation

BTS Bureau of Transportation Statistics

BWI Baltimore/Washington International Thurgood Marshall 

DOT Department of Transportation

FAA Federal Aviation Administration

FRA Federal Railroad Administration

HSIPR High-Speed Intercity Passenger Rail

NextGen Next Generation Air Transportation System

PRIIA Passenger Rail Investment and Improvement Act of 2008

Recovery Act American Recovery and Reinvestment Act of 2009

RITA Research and Innovative Technology Administration

RRIF Railroad Rehabilitation and Improvement Financing

TIFIA Transportation Infrastructure Finance and Innovation Act

of 1998

TIGER Transportation Investment Generating Economic

Recovery

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. The published product may be reproduced and distributed in its entirety 

without further permission from GAO. However, because this work may contain 

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Page 1 GAO-13-691 Intermodal Transportation

441 G St. N.W.

Washington, DC 20548

August 2, 2013

The Honorable John D. Rockefeller IV

Chairman

The Honorable John Thune

Ranking Member

Committee on Commerce, Science, and Transportation

United States Senate

The Honorable Bill Shuster

Chairman

The Honorable Nick J. Rahall, II

Ranking Member

Committee on Transportation and Infrastructure

House of Representatives

Mobility—the movement of passengers and goods through the 

transportation system—is critical to the nation’s economic vitality and the 

quality of life of its citizens. Mobility provides people with access to goods, 

services, recreation, and jobs; provides businesses with access to 

material, markets, and people; and promotes the movement of personnel 

and material to meet national defense needs. However, increasing 

passenger travel has led to growing congestion in the nation’s 

transportation system, and projections of future passenger travel suggest 

that this trend is likely to continue. For example, the Federal Aviation 

Administration (FAA) estimates that the number of airplane passengers 

using U.S. airports is expected to grow by 23 percent from over 730 

million in 2011 to nearly 900 million by 2021. At the same time, intercity 

passenger rail service, provided by the National Railroad Passenger 

Corporation, or Amtrak, has been increasingly used by passengers to 

travel between cities, as airlines have reduced the number of shortdistance flights and airports have implemented heightened security 

procedures in the wake of the events of September 11, 2001. Amtrak’s 

ridership has increased by nearly 55 percent over the last 15 years to 

over 31 million riders in 2012, with nearly 27 million of these passengers 

traveling over short distance corridors (which Amtrak defines as less than 

750 miles), such as the Northeast Corridor between Washington, D.C., 

and Boston, Massachusetts, or the Cascades Corridor between Seattle, 

Washington, and Portland, Oregon.

The integration of air and intercity passenger rail service has been 

suggested by some transportation experts as a strategy to increase 
Page 2 GAO-13-691 Intermodal Transportation

mobility and reduce congestion in the United States based on 

experiences in other parts of the world. For example, European 

transportation policy has increasingly focused on intermodal 

transportation—that is, a system that connects the separate 

transportation modes and allows a passenger to complete a journey using 

more than one mode—and included improving connections between 

airports and intercity passenger rail, also known as air-rail connections.

We reviewed intermodal connectivity at airports in 2005, and found that 

air-rail connections involving intercity passenger rail were limited.1

In the FAA Modernization and Reform Act of 2012, Congress directed us 

to examine issues related to air-rail connectivity.

Such 

integration can be challenging, in part because of the costly long-term 

investments that are needed to connect airports to intercity passenger rail 

and difficulties in developing intermodal services and ticketing options 

that are attractive to travelers. Furthermore, U.S. intercity passenger rail 

service offers limited service in many heavily traveled corridors, and its 

overall service has slower average speeds relative to other transportation 

modes, often a result of delays from sharing track with freight rail and 

commuter rail services.

2

To address these objectives, we obtained and analyzed information from 

a variety of sources. To obtain insight on issues related to air-rail 

connectivity, we collaborated with the National Academy of Sciences to 

identify 25 experts from the aviation and rail industries, Amtrak, state and 

local governments, academia, and the private sector. These experts were 

selected based on their knowledge of one or more of the following topic 

areas: intermodalism, airlines and the air travel industry, airport 

operations, the rail industry, and passenger travel. We identified an 

This report discusses 

(1) the nature and scope of existing air-rail connectivity in the United 

States; (2) the benefits and costs of developing air-rail connectivity; (3) 

the factors that facilitate and hinder the development and use of air-rail 

connectivity; and (4) potential strategies, including lessons learned from 

other countries, that may help inform deliberations regarding air-rail 

connectivity policy.

 1

GAO, Intermodal Transportation: Potential Strategies Would Redefine Federal Role in 

Developing Airport Intermodal Capabilities, GAO-05-727 (Washington, D.C.: July 26,

2005).

2

Pub. L. No.112-95, § 810, 126 Stat. 11,123 (Feb. 14, 2012).
Page 3 GAO-13-691 Intermodal Transportation

additional 17 experts in these fields through a review of academic 

literature, our previous work, and interviews with stakeholders. We 

developed and conducted a web-based survey in which we asked these 

42 experts for their views on benefits of air-rail connectivity, factors that 

facilitate and hinder its development and use, differences between air-rail 

connectivity efforts in the United States and Europe, and strategies that 

could improve air-rail connectivity. We conducted the survey in two 

stages. The first round of the survey asked the experts to respond to five 

open-ended questions about various aspects of air and intercity 

passenger rail connectivity.3 We analyzed the responses provided by the 

experts and developed close-ended questions for the second round of the 

survey where we asked each expert to rate the ideas and other 

information that came from the first part of the survey.4 The information 

and perspectives that we obtained from the expert survey may not be 

generalized to all experts that have an interest or knowledge of air-rail 

connectivity issues. The full survey and responses are contained in an esupplement to this report.5

In addition, we reviewed federal laws related to air and intercity 

passenger rail transportation, and strategic plans from Amtrak and the 

Department of Transportation (DOT). We reviewed and synthesized 

information from academic literature and our body of work on air-rail 

connectivity and air-rail “code-share” agreements in the United States and 

internationally. We obtained data from the Bureau of Transportation 

Statistics (BTS) on the location of Amtrak stations near large and medium 

hub airports and determined the linear distance between each airport and 

the nearest Amtrak station.6

 3

We received a 95 percent (40 out of 42) response rate for the first stage of the survey.

Based on the BTS data’s use as a widely 

accepted federal statistical database, we determined these data to be 

generally reliable for our purpose, which was to provide context on 

existing air-rail connectivity. We reviewed completed, ongoing, and future 

4

We received a 98 percent (41 out of 42) response rate for the second stage of the 

survey. 

5

GAO-13-692SP.

6

FAA has established airport hub size categories based on the number of passengers 

boarding an aircraft (enplaned) for all operations of U.S. carriers in the United States. A 

large hub commercial service airport has 1 percent or more of total annual passenger 

boarding. A medium hub commercial service airport has at least 0.25 percent but less 

than 1 percent of total annual passenger boarding.
Page 4 GAO-13-691 Intermodal Transportation

air-rail connectivity efforts at eight large and medium hub airports in the 

United States, and interviewed various stakeholders at each site, 

including airport authorities, state and local transportation agencies, local 

transportation-planning organizations, and air and rail industry 

associations.7

We conducted this performance audit from August 2012 to August 2013 

in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform the audit to obtain 

sufficient, appropriate evidence to provide a reasonable basis for our 

findings and conclusions based on our audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

These eight airports were selected to include airports that 

have recently planned, constructed, or completed an air-rail project and 

are dispersed in various regions of the country. Lastly, we interviewed 

officials from DOT and Amtrak, transportation experts, and 

representatives from U.S. airlines and industry associations to obtain their 

perspectives on air-rail connectivity issues.

Additional information on our methodology and the experts who 

participated in our survey are found in appendixes I and II, respectively.

For the purposes of this report, an air-rail connection refers to a 

connection between an airport terminal and an intercity passenger rail 

station (in other contexts, an air-rail connection may refer to a connection 

between an airport terminal and an intracity rail station that serves other 

forms of local rail, such as commuter rail or a subway system). An air-rail 

connection facilitates mobility between a rail station and an airport 

terminal through a variety of modes and methods, such as an airport 

shuttle, local transit connection, automated people mover or guideway 

car, or by walking. Depending on the extent of the connectivity, intercity 

passenger rail can perform three main roles for air passengers.

 7

We reviewed air-rail connectivity efforts at Baltimore/Washington International Thurgood 

Marshall (BWI) Airport, Bob Hope Airport, Chicago O’Hare International Airport, 

Dallas/Fort Worth International Airport, Miami International Airport, General Mitchell 

International Airport, Norman Y. Mineta San Jose International Airport, and Newark Liberty 

International Airport. 

Background
Page 5 GAO-13-691 Intermodal Transportation

• First, intercity passenger rail may serve as a short-distance 

connection to the nearest local airport from a metropolitan area along 

a more extensive intercity rail corridor.

• Second, intercity passenger rail may serve as a competitive 

alternative to air travel. For example, for distances less than 500 

miles, our prior work has shown that intercity passenger rail, 

particularly high-speed rail, offers some potential advantages over air 

travel, including reduced times for security screening and baggage 

checks.8

• Third, intercity passenger rail can serve as part of an integrated 

intercity transportation solution with air travel, where the passenger 

travels significant distances using both modes. For these types of airrail connections, travel may be further integrated by code-sharing, 

which refers to the practice of airlines applying their names and selling 

tickets to rail service operated by other organizations, such as 

Amtrak.9

Amtrak provides intercity passenger service to 46 states and the District 

of Columbia, operating over a 22,000-mile network, mainly using track 

owned by freight railroads. Amtrak owns about 655 miles of rail lines, 

primarily on the Northeast Corridor between Boston, Massachusetts, and 

Washington, D.C. Most of Amtrak’s passengers travel within the 

Northeast Corridor or over relatively short-distances, though Amtrak also 

operates a number of long distance routes across the country. The speed 

of service varies across the country. For example, according to Amtrak, 

its Heartland Flyer service connecting Oklahoma City, Oklahoma, and 

Fort Worth, Texas, averages about 50 miles per hour (mph) over the 206-

mile corridor while its Acela Express higher-speed service averages less 

than 80 mph throughout the Northeast Corridor (reaching top speeds up 

to 150 mph). While Amtrak’s Acela Express service is currently the fastest 

intercity passenger rail service in the United States, California has begun 

 8

GAO, High Speed Passenger Rail: Future Development Will Depend on Addressing 

Financial and Other Challengers and Establishing a Clear Federal Role, GAO-09-317

(Washington, D.C.: Mar. 19, 2009).

9

For example, a code-sharing agreement between an airline and Amtrak would allow 

passengers to make reservations and purchase a ticket with the airline for both air and rail 

travel.
Page 6 GAO-13-691 Intermodal Transportation

developing a 520-mile high-speed rail line designed to operate at speeds 

up to 220 mph.10

Transportation projects at airports are typically initiated and developed by 

local transportation agencies, including some combination of state 

departments of transportation, local planning bodies, and other local 

agencies. While roles may vary, one or more state and local 

transportation agency will generally take the lead in project development 

and implementation. Airports typically are also heavily involved with 

developing intermodal capabilities on airport property. This is especially 

true if the project involves construction of a major intermodal facility. For 

example, the Miami International Airport, working in cooperation with the 

Florida Department of Transportation, has been one of the leaders in the 

development of the Miami Intermodal Center, which will provide on-site 

access to Amtrak, multiple other rail systems, local transit services, and a 

rental car center through the use of an automated people mover.11

Federal laws and planning guidance have limited emphasis on air-rail 

connectivity, but have a broad goal of establishing a system-wide, 

intermodal approach to addressing transportation needs. For example, 

federal aviation policy encourages the development of intermodal 

connections on airport property and systems that serve air transportation 

passengers efficiently and effectively and promote economic 

Airlines also play a role in developing intermodal projects at airports. Use 

and lease agreements between airlines and airports are a major revenue 

source for most large airports, and because of this financial arrangement, 

airlines may have influence in or participate in airport decision making. 

The ability of airlines to participate in decision making depends on the 

specific airport and the structure of the lease agreements between the 

airport and airlines serving that airport. Amtrak generally becomes 

involved in the planning process at airports when a state or local 

government proposes a project that could potentially affect its intercity 

passenger rail service.

 10For more information, see GAO, California High-Speed Passenger Rail: Project 

Estimates Could Be Improved to Better Inform Future Decisions, GAO-13-304

(Washington, D.C.: Mar. 28, 2013).

11An automated people mover is a guided transit mode with fully automated operation, 

featuring vehicles that operate on “guideways” with exclusive right-of-way, such as an 

automated monorail system.
Page 7 GAO-13-691 Intermodal Transportation

development.12 Additionally, FAA’s 2012 reauthorization legislation directs 

the Secretary of Transportation to encourage airport planners to consider 

passenger convenience, airport ground access, and access to airport 

facilities during the development of intermodal connections on airport 

property.13 Similarly, the Passenger Rail Investment and Improvement Act 

of 2008 (PRIIA) authorized development of high-speed intercity 

passenger rail corridors and the American Recovery and Reinvestment 

Act of 2009 (Recovery Act) appropriated $8 billion to fund development of 

these corridors and intercity passenger-rail projects.14 In June 2009, the 

Federal Railroad Administration (FRA) established the High-Speed 

Intercity Passenger Rail (HSIPR) program that provides discretionary 

grants for high-speed or intercity passenger rail projects. In allocating 

funds, PRIIA directed FRA to give greater consideration to projects that, 

among other things, encourage intermodal connectivity among train 

stations, airports, subways, transit, and other forms of transportation.15

However, federal policy for surface transportation, aviation, and 

passenger rail is established through separate legislation. For example, 

the planning and funding for highway and transit projects are addressed 

under the Moving Ahead for Progress in the 21st Century Act,16

While the federal government does not provide funding specifically for airrail connections, it has established a number of other funding 

mechanisms that can be used to enhance elements of air-rail 

connectivity. (See app. III.) Most federal funding for transportation 

projects is provided through grant programs through the individual 

specific modal administration and reserved for improvements specific to 

that mode. For example, most direct federal financial support for airport 

capital projects has been provided through grants from FAA’s Airport 

the 

planning and funding of U.S. airports is addressed under the FAA 

Modernization and Reform Act of 2012, and the planning and funding for 

intercity passenger rail is addressed under PRIIA.

 1249 U.S.C. § 47101(a)(5).

13Pub. L. No.112-95, §131, 126 Stat. 11, 21 codified at 49 U.S.C. § 47101(g)(2)C).

14Pub. L. No. 110-432, div. B, title V, § 501,122 Stat. 4848, 4907, 4959 (Oct. 16, 2008); 

Pub. L. No. 111-5, 123 Stat. 115, 208 (Feb 17, 2009).

15Pub. L. No. 110-432, div. B, title V, § 501, 122 Stat. 4848, 4907, 4962.

16Pub. L. No. 112-141. 126 Stat. 405 (July 6, 2012).
Page 8 GAO-13-691 Intermodal Transportation

Improvement Program (AIP).17 While AIP grants may be used to fund 

intermodal projects, an airport’s use of its funds is generally restricted to 

an airport project that is owned or operated by the airport sponsor and 

that is directly and substantially related to the air transportation of 

passengers or property.18 Airports have funded portions of light rail and 

transit (such as subway or bus) using AIP funds at airports meeting these 

restrictions.19

Federal oversight of air-rail projects is primarily divided across DOT’s 

respective modal administrations, though DOT has established some 

practices to coordinate oversight of intermodal projects. For example, for 

an air-rail connection project, the aviation component is overseen by FAA, 

while the rail component is overseen by FRA. As another example, 

according to DOT, its Research and Innovative Technology 

Administration (RITA) works closely with DOT’s modal administrations to 

improve intermodal cooperation, solve transportation challenges that cut 

across modal boundaries, and remove barriers to intermodal projects 

through a variety of research efforts.

Funding for intercity passenger rail has been provided in the 

form of operating and capital subsidies to Amtrak, as well as the HSIPR 

grant program.

20

In contrast to the United States, European policy and European 

governments have promoted connections between passenger high-speed 

rail systems and airports as part of establishing high-speed rail service 

between cities as an alternative to air and car travel. Since 1992, the 

In addition to these efforts, in 2012 

DOT established a working group consisting of representatives from each 

modal administration to track intermodal initiatives and projects. The goal 

of the working group is to provide non-monetary resources such as 

recommendations of policies to promote intermodal transportation 

projects, including air-rail connectivity projects.

 17AIP grants are one of five major sources of funding for airport improvements. Airports 

also typically make use of four other major sources to fund capital projects: tax-exempt 

bonds, state and local grants, airport revenue, and passenger facility charges.

1849 U.S.C. §§ 47107(b)(1), 47133(a).

19Light rail refers to trains that may operate on exclusive tracks or on tracks in the street 

on the same level with pedestrians and car traffic.

20RITA is responsible for coordinating, facilitating, and reviewing DOT’s programs and 

activities to identify research duplication and opportunities for joint efforts and to ensure 

that research, development, and technology activities are meeting intended goals.
Page 9 GAO-13-691 Intermodal Transportation

European Commission has periodically published a common 

transportation policy in response to increased ground and air congestion, 

as well as concerns about the dependence on oil and the level of carbon 

emissions resulting from the current transportation system. A key 

component of the European Commission’s transportation policy is 

improving the connections between air and rail, thereby transforming 

competition between those modes into complementary service using 

high-speed train connections located at European airports. The current 

European Commission transportation policy, adopted in 2011, aims to 

connect all 37 core airports to the rail network, preferably through highspeed rail, and shift a majority of medium-distance passenger 

transportation (which the European Commission defines as under 300 

kilometers or 186 miles) to the passenger rail network by 2050.21

Beyond these policy differences, our prior work has also noted that 

differences related to population density, geography, and private 

automobile use have contributed to differences in the development and 

use of air-rail connections in Europe compared to the United States.22

This prior work has highlighted the greater population density of 

European cities and that downtowns are major destination points for 

passengers as key differences that affect the use of intermodal systems.

While some U.S. cities have population densities comparable to 

European cities, in general, U.S. cities are more decentralized. 

Furthermore, distances between many major cities in the United States 

are generally greater than in Europe, which can affect the ability of 

intercity passenger rail to be competitive with air travel, depending on 

price and the speed of service. In addition, private automobile use has 

affected air-rail connections. Specifically, the rate of car ownership is 

generally higher in the United States compared to Europe, while at the 

same time, retail gasoline prices in the United States are much lower than 

in Europe because of substantially lower taxes.23

 21European Commission, Roadmap to a Single European Transport Area —Towards a 

Competitive and Resource Efficient Transport System, COM (2011) 144 final (Brussels, 

BD: Mar. 28, 2011).

Furthermore, in the 

United States, surface transportation policy has primarily focused on 

developing and improving highways, while the transportation policy of 

22GAO-05-727. 

23As of May 30, 2013, retail gas prices in European Commission countries averaged 

$7.11 per gallon, while in the United States, gas prices averaged $3.66 nationwide. 
Page 10 GAO-13-691 Intermodal Transportation

European countries have placed a greater comparative emphasis on the 

development of intercity passenger rail and public transportation.

Accordingly, people traveling to airports in the United States are more 

likely than in Europe to drive and park their cars at the airports, which 

could reduce the demand for (as well as the benefits of) intercity 

passenger rail connections at U.S. airports.

Beyond Europe and the United States, the integration of air travel and 

intercity passenger rail varies. For example, in Japan, air service and 

high-speed intercity passenger rail compete and do not complement each 

other as in Europe.24 The uniqueness of Japan’s transportation system 

stems from the fact that two-thirds of its population, or almost 100 million 

people, live in a narrow, densely populated corridor. Furthermore, Japan 

has nearly 5,600 miles of private tollways, which makes intercity travel by 

car expensive. In China, the Shanghai Railway Bureau and China 

Eastern Airlines commenced operations of air-rail combined services in 

May 2012 to and from Shanghai Hongqiao International Airport, marking 

China’s first air-rail combined service. The service allows passengers to 

transfer between domestic or international air services and train 

operations with a single ticket.

 24Reinhard Clever and Mark M. Hansen, “Interaction of Air and High-Speed Rail in Japan,”

Transportation Research Record: Journal of the Transportation Research Board, no. 2043

(2008).
Page 11 GAO-13-691 Intermodal Transportation

Most major U.S. airports have some degree of physical proximity to 

intercity passenger rail stations; however, few are collocated with rail 

stations.25 Specifically, our analysis found that 42 of the 60 large and 

medium hub airports in the contiguous United States are located within 10 

miles of an Amtrak station; 21 of the 42 airports are within 5 miles of a 

station.26 (See fig. 1.) Newark Liberty International Airport and Bob Hope 

(Burbank) Airport are the only airports where passengers can access the 

Amtrak stations via an automated people mover (Newark) or by walking 

(Burbank).27 Airline passengers at Miami International Airport will be able 

to connect to Amtrak via an automated people mover upon completion of 

the Miami Central Station in 2014. Amtrak officials noted that, in some 

locations, it provides service that may operate in close proximity to an 

airport, but may not have an Amtrak station near that airport.28

 25To determine the extent that air-rail connectivity has been developed in the contiguous 

United States, we selected 60 airports, consisting of the 28 large hubs, and the 32 

medium hub airports located in the contiguous United States based on the 2011 FAA’s Air 

Carrier Activity Information System database for analysis. We limited our analysis to the 

60 major airports in the contiguous United States because they accounted for 

approximately 86 percent of U.S. passenger enplanements for calendar year 2011. 

Passengers at the nation’s other major airports have to rely on another 

26We based our analysis on linear distance using latitude and longitude information for 

each of the 60 airports and the nearest Amtrak station; the linear distance may not reflect 

the actual distance that passengers experience depending on the transportation mode, 

local roads, or paths used. For a complete list of linear distances between large and 

medium hub airports and the nearest Amtrak station, see appendix IV. 

27Bob Hope Airport also provides free shuttle services to the Amtrak station at the airport 

and downtown Burbank.

28For example, at Theodore Francis Green State Airport in Warwick, Rhode Island, 

Amtrak’s service passes through but does not stop at a local commuter rail station located 

near the airport terminal.

Connectivity between 

Major Airports and 

Intercity Passenger 

Rail Remains Limited, 

as Does Passenger 

Usage

Most Major Airports Are 

near Intercity Passenger 

Rail Stations, but Air-Rail 

Connectivity is Rare
Page 12 GAO-13-691 Intermodal Transportation

transportation mode such as shuttle, taxi, or transit (intracity rail, subway, 

or bus) to connect to an Amtrak station and some passengers must make 

multiple connections. For example, passengers at Baltimore/Washington 

International Thurgood Marshall (BWI) and Milwaukee’s General Mitchell 

International can take a free airport shuttle to and from Amtrak stations, 

while passengers choosing to take public transportation to access Amtrak 

from Norman Y. Mineta San Jose International Airport would have to take 

both a free shuttle and light rail. However, some officials we interviewed 

told us that passengers are less willing to consider intermodal travel as 

the number of modes needed to complete a single trip increases.

Figure 1: Large and Medium Hub Airports within 10 Miles of an Amtrak Station, May 2013

Note: The distance between each airport and the nearest Amtrak station was calculated using the 

linear distance between longitude and latitude coordinates of each large and medium hub airport and 

each Amtrak station, as identified in the National Transportation Atlas Database 2012. The distance 

between each airport and the nearest Amtrak station reflects the linear distance between the two 
Page 13 GAO-13-691 Intermodal Transportation

locations, and may be affected by existing buildings, roads, bridges, or other obstacles in the path of 

a traveler connecting between an airport and an Amtrak station. Amtrak officials noted that, in some 

locations, it provides service that may operate in close proximity to an airport, but may not have an 

Amtrak station near that airport. For detailed information on the distances between each large and 

medium hub airport and Amtrak stations, see appendix IV.

Stakeholders at many of the airports we visited have placed a greater 

emphasis on intracity connectivity (or connections within a local 

metropolitan region) to the airport through local rail or other transit, as 

opposed to connectivity through intercity passenger rail. While a local 

transit system may provide a connection between an airport and intercity 

passenger rail, such a connection is generally not the primary goal. For 

example, at Dallas/Fort Worth International Airport, officials are working 

with the Dallas Area Rapid Transit agency to provide an intracity rail 

connection to the airport from downtown Dallas by 2014. Officials noted 

that an intracity rail connection was preferable to connectivity through 

Amtrak because of the limited frequency of service provided by Amtrak in 

the region, among other factors. When the extension is completed, airport 

passengers would be able to connect to the Amtrak station located in 

downtown Dallas through the intracity rail connection. Similarly, officials at 

Norman Y. Mineta San Jose International Airport in California noted that 

policymakers should focus on connecting intracity rail to their airport, 

rather than intercity passenger rail, in part, because the San Jose airport 

is not a hub airport and most of its customers reside in the surrounding 

San Francisco Bay area.

Amtrak and state transportation agencies are considering projects to 

expand connectivity with airports. Amtrak’s strategic plan states that it will 

increase connectivity with airports in key markets and has established a 

strategic goal to increase the number of air-rail connections in the 

Northeast Corridor from two to five by 2015.29

 29Amtrak, Amtrak Strategic Plan, FY 2011–FY 2015. 

However, Amtrak officials 

we spoke with stated that they do not believe Amtrak will achieve this 

goal because of limited available funding for intercity passenger rail. 

Some states, such as California, Illinois, and Texas, are looking at options 

to enhance air-rail connectivity by developing high-speed rail connections 

at nearby large and medium hub airports. For example, in addition to 

Illinois’ development of high-speed rail between Chicago and St. Louis, 

several options for possible future opportunities for improving Amtrak 
Page 14 GAO-13-691 Intermodal Transportation

passengers’ connectivity to Chicago O’Hare International Airport have 

been proposed.30

Studies and data, while limited, suggest that relatively few passengers 

and airport employees use the limited air-rail connections available to 

travel to and from U.S. airports. Ground access studies have shown that 

intercity passenger rail is rarely used to connect to airports compared to 

other modes of transportation. For example, a 2012 study stated that 

Amtrak accounted for 3 percent of ground access mode share at Newark 

Liberty International; 2 percent at BWI, and less than 1 percent at Bob 

Hope Airport.31 By comparison, another study observed that at some 

European airports with direct air-rail connections, long-distance intercity 

passenger rail accounts for 20 to 25 percent of the ground access mode 

share.32 In general, transportation and airport officials told us that demand 

for public transportation options to airports is limited, as the vast majority 

of passengers still use personal automobiles to access the airport.

 30The Chicago Department of Transportation’s Union Station Master Plan (2012) 

recommends reconfiguring the station’s tracks and platforms in a manner that could allow 

some Amtrak trains to serve Chicago O’Hare International Airport in addition to Union 

Station. According to the Chicago Department of Transportation, it is currently conducting 

a second stage of the Master Plan to estimate the amount of train and passenger capacity 

that the proposed improvements could add, building the case for the future federal, state, 

and local funding support needed to make the improvements.

31Benjamin R. Sperry, Shawn Larson, David Leucinger, Scott Janowiak, and Curtis A. 

Morgan, “Intercity Passenger Rail Access to Airports: Case Study in Milwaukee, 

Wisconsin,” Transportation Research Record: Journal of the Transportation Research 

Board, no. 2300 (2012). 

32Matthew A. Coogan, “Quantifying the Scale of Air/Rail Complementarity and Air/Rail 

Competition in Europe and the United States,” (paper presented at the annual meeting of 

the Transportation Research Board, Washington, D.C., January 2012).

Few Passengers Use AirRail Connections
Page 15 GAO-13-691 Intermodal Transportation

The only current code-sharing agreement for air and rail travel in the 

United States is at Newark Liberty International Airport, though codesharing has been implemented or explored at other airports.33 The codesharing agreement between United Airlines and Amtrak allows 

passengers to make reservations with United Airlines for both air and rail 

travel, and Amtrak provides the connecting service on its trains between 

Philadelphia, Pennsylvania; Wilmington, Delaware; Stamford or New 

Haven, Connecticut, and to anywhere United Airlines flies from Newark 

Liberty International Airport.34 According to Amtrak data, about 24,000 

passengers a year take Amtrak to Newark to connect to United Airlines 

flights, with 90 percent of those passengers originating from Philadelphia.

However, United Airlines representatives pointed out that most 

passengers at the Newark Liberty International Airport rail station—which 

Amtrak estimated at over 120,000 passengers in fiscal year 2012—are 

not traveling through the code-share agreement. No additional code 

share agreements are currently planned between Amtrak and other 

airlines we contacted.35

 33For example, at BWI, Icelandair and Amtrak had put in place a code share agreement

prior to Icelandair’s discontinued service at BWI in 2008. Additionally, Amtrak was 

approached by Midwest Airlines at General Mitchell International, but both Amtrak and 

Midwest Airlines agreed that there was no benefit to a formal code share program. Airline 

officials cited operational and logistical challenges such as incompatible reservation 

systems, lack of reliable and frequent rail service, as well as lack of control and liability 

from rail delays as reasons for not pursuing code-share agreements.

Representatives from the airlines and Amtrak told 

us that code-sharing agreements are generally most effective when the 

rail station is located at the airport and within a high-traffic rail corridor, 

which is the case with Newark Liberty International Airport and the 

Northeast Corridor. As previously noted, few rail stations are collocated 

with a major airport. Both airline and Amtrak officials indicate that for 

code-share agreements, airlines require frequent rail service with 

minimum passenger transfer time between modes. Amtrak officials stated 

that they provide that frequency of service in very few markets, generally 

located on Amtrak’s Northeast Corridor serving highly populated 

metropolitan areas.

34Amtrak and Continental Airlines began the code share agreement in 2001. With 

Continental’s merger with United Airlines, this relationship has transitioned to one with 

United. The agreement also allows Amtrak to transport airline passengers between 

Newark Liberty International, BWI, and Philadelphia International during inclement 

weather or when there are disruptions to flight services. 

35We contacted United Airlines, Delta Air Lines, U.S. Airways, and American Airlines. 

Collocated Airport 

Terminals and Rail 

Stations Allow for Code 

Sharing
Page 16 GAO-13-691 Intermodal Transportation

We found that air-rail connectivity has the potential to provide a range of 

mobility, economic, and environmental benefits. In our discussions with 

stakeholders, including state departments of transportation, local 

transportation-planning organizations, and airlines; our review of 

academic literature; and the expert opinions obtained from our survey, we 

found that a general consensus exists that air-rail connectivity can 

provide a range of mobility benefits for travelers; however, we found less 

agreement exists on the importance and extent of other types of benefits, 

including economic and environmental benefits. Table 1 shows the 

benefits most frequently cited as “very important” by the experts, five of 

which focus on mobility benefits.36 However, our review suggests that the 

particular benefits for a given project are generally site-specific, and 

depend on the particular characteristics of the rail operators, the airports, 

and underlying regional characteristics. As a result, the benefits we 

identified through our work are not generalizable to all air-rail 

connections.

 36Experts rated each of the potential benefits identified in the first stage as “very 

important,” “important,” “somewhat important,” “not important,” “not a benefit,” or that they 

had “no opinion.” For more information on our survey and results, see appendix I and 

GAO-13-692SP respectively. 

Air-Rail Connectivity 

May Provide a Range 

of Benefits for 

Passengers and 

Others, but Costs Can 

Be Significant

Benefits
Page 17 GAO-13-691 Intermodal Transportation

Table 1: Benefits of Air-Rail Connectivity Most Frequently Cited as “Very Important”

by Experts Surveyed

Traveler Benefits • Increased passenger convenience

• Increased reliability of travel to the airport

• Increased number of travel options for passengers

• Reduced travel time to and from airports

• Increased passenger satisfaction

Economic Benefits • Increased catchment area for airports

• Increased catchment area for airlines

• Allows short-haul flights to be replaced by intercity rail 

connections

Environmental Benefitsa • Reduced carbon emissions

• Reduced energy use

Source: GAO analysis.

Note: We identified the most important benefits based on the number of respondents in the survey 

who rated these benefits as “very important.”

a

Experts in our survey suggested that the reduced carbon emissions and energy use could result 

from, among other factors, a reduction in automotive miles traveled to the airport and through the 

substitution of intercity passenger rail service for short-distance flights.

Air-rail connections can potentially provide mobility benefits, such as 

increased options for passengers connecting to the airport, and improved 

convenience for airport and airline customers. Specifically, over half of the 

experts responding to our survey agreed that increasing passenger 

convenience and travel options were “very important” benefits of air-rail 

connectivity,37

 37Specifically, 23 of 41 experts that responded to the survey rated increased passenger 

convenience as a “very important” benefit while 21 of 40 responding experts rated 

increased travel options as a “very important” benefit. The total number of experts who 

responded to each survey question slightly varied.

and airport representatives cited both benefits as driving 

factors for intermodal projects at a number of our site visits. For example, 

representatives at Miami International Airport noted that in the 1980s a 

lack of ground transportation options, including connectivity to rail, had 

reduced passenger traffic at the airport. Beginning in 2001, the Florida 

Department of Transportation began to construct an intermodal center, 

which will provide passenger access to the airport through multiple 

ground transportation modes, including intercounty and intercity 

passenger rail. According to airport representatives, directly connecting 

Amtrak service to the airport will provide an additional option to 

passengers connecting to the airport and encourage passengers to be 
Page 18 GAO-13-691 Intermodal Transportation

more willing to try other non-automotive forms of transportation. 

Construction of the new Amtrak terminal (Miami Central Station) began in 

2011, and representatives anticipate the terminal will be completed in 

2014. (See fig. 2.) Furthermore, air-rail connections can provide airport 

access to commuter trains in addition to intercity trains operated by 

Amtrak, as many of the Amtrak stations located near airports are served 

by both types of services. In addition, rail connectivity to airports has the 

potential to improve the passenger experience traveling to the airport. In 

particular, half of the experts (22 of 41) rated increased reliability of travel 

to the airport, and nearly half (18 of 40) rated reductions in the travel time 

to and from the airport as very important benefits of air-rail connections. 

Representatives from the airlines and airports we interviewed noted that 

their employees might also similarly benefit from an air-rail connection, 

specifically by providing increased options to and from the airport and 

improved convenience for airport and airline employees. However, 

representatives from one airline cautioned that the extent of any benefits 

would depend upon the cost of the air-rail connection and how such a 

connection was funded.

Figure 2: Construction of the Miami International Airport Miami Central Station, 

February 2013
Page 19 GAO-13-691 Intermodal Transportation

Air-rail connections also have the potential to provide economic benefits 

for some transportation operators, such as an increased customer base. 

We found that some of the experts (16 of 40) participating in our survey 

and a majority of the stakeholders at six of our eight site visits highlighted 

the potential for intercity rail to access populations outside of the major 

metropolitan area served by a large or medium hub airport. Specifically, 

the experts and stakeholders noted that an air-rail connection may 

increase an airport’s or airline’s passenger base by attracting additional 

passengers from outside an airport’s local market, thus potentially 

generating additional revenue for airports and airlines in that metropolitan 

area. Some studies suggest that the existence of an air-rail connection 

affects a passenger’s choice of airport in areas where multiple options 

exist. In particular, a recent study of passengers using Amtrak to connect 

to General Mitchell International Airport in Milwaukee found that 

approximately one-third of passengers reported that they would have 

used one of the two Chicago area airports if the Amtrak-Mitchell Airport 

connection was not available.38

In addition, air-rail connectivity could allow for the substitution of rail 

service for short-haul flights, freeing up capacity for long-haul flights and 

reducing airport and airspace congestion, though the importance of this 

benefit varies depending on the airport and the rail service’s operating 

characteristics. Specifically, nearly half of the experts (19 of 41) in our 

survey and stakeholders at three of our eight site visits noted that the 

potential replacement of short-haul flights by rail was a “very important”

potential benefit of air-rail connectivity. Our prior work has found that 

intercity passenger rail, particularly high-speed rail, could serve as a 

substitute for air service for distances of up to 500 miles.

In addition, Amtrak service can also 

complement existing rail connections made by commuter rail, offering 

additional frequencies between points served by the commuter trains.

However, where transit already offers a connection between a city center 

and airport, stakeholders at two of our eight site visits noted that an 

intercity passenger rail connection to the airport may potentially compete 

with transit service in the same area, thus limiting any increase in airport 

or airline customers and benefits from enhanced connectivity.

39

 38Benjamin R. Sperry and Curtis A. Morgan, Texas Transportation Institute, “Intercity 

Passenger Rail: Implications for Urban, Regional, and National Mobility,” University 

Transportation Center for Mobility Report 11-10-75 (College Station, TX: December 2011).

Our previous 

39GAO-09-317.
Page 20 GAO-13-691 Intermodal Transportation

work on intercity passenger rail has found that for rail transportation to 

capture the market share necessary to reduce air travel congestion, the

distance between cities must be short enough to make rail travel times 

competitive with air travel times (at comparable costs and levels of 

comfort).40 In practice this has been observed to a great extent in the 

Northeast Corridor, where a number of major urban areas are located 

within close proximity and where there are significant constraints on the 

capacity within the air transportation system. For example, Amtrak’s 

share of the air-rail market for trips between Washington, D.C., and New 

York City has increased from 37 percent to 75 percent since the 

introduction of the higher speed Acela Express service in 2000. However, 

studies of air-rail connections in other countries suggest that the complete 

abandonment of air service in response to the introduction of rail service 

serving the same markets is rare.41 Furthermore, this benefit may be 

limited given that most airports in the United States are not currently 

capacity-constrained, though we have previously reported that FAA 

projects that a number of airports will be significantly capacity-constrained 

and thus congested within the next 15 years.42

Over one-third of the experts participating in our survey rated 

environmental benefits, including reduced carbon emissions (17 of 41), 

and reduced energy use (15 of 40), as “very important” benefits of air-rail 

connectivity. For the European Commission, enhancing air-rail 

connectivity has been embraced as part of its strategy to reduce 

For example, officials from 

Chicago O’Hare International Airport stated that because their airport is 

not capacity-constrained, the benefits from a direct connection with 

Amtrak would be limited. Amtrak officials noted that they are exploring 

options to connect to Chicago O’Hare International Airport, but noted that 

it was premature to speculate on the benefits of such a connection, 

particularly given Amtrak’s ongoing efforts to upgrade track speeds to 

major cities from Chicago.

 40GAO, Intercity Passenger Rail: Issues for Consideration in Developing an Intercity 

Passenger Rail Policy, GAO-03-712T (Washington, D.C.: Apr. 30, 2003).

41Transportation Research Board, Innovative Approaches to Addressing Aviation Capacity 

Issues in Coastal Mega-Regions, Airport Cooperative Research Program Report 31 

(Washington, D.C.: 2010).

42GAO, National Airspace System: Regional Airport Planning Could Help Address 

Congestion If Plans Were Integrated with FAA Airport Decision Making, GAO-10-120 

(Washington, D.C.: Dec. 23, 2009).
Page 21 GAO-13-691 Intermodal Transportation

greenhouse gases, including carbon emissions, by 60 percent by 2050 

while improving mobility.43 However, academic studies vary on the extent 

to which environmental benefits can be achieved from increased air-rail 

connectivity.44 For example, energy savings from high-speed rail 

connectivity may depend, in part, on the extent that passengers use rail to 

connect to the airport rather than other automotive transportation.

45

Studies have also suggested that the substitution of long-distance flights 

for short-haul flights that have been replaced by rail service could 

potentially increase carbon emissions.46

Expanding the current intercity passenger rail network and connecting it 

to airports would be expensive. However, the costs of facilitating 

connections between intercity passenger rail stations and airports could 

vary significantly, depending in part on the complexity and scope of the 

project. (See table 2.) Air-rail connectivity efforts may be as simple as 

providing shuttle bus service between the Amtrak station and the airport 

terminal or as complex as relocating the intercity passenger rail station 

closer to the airport and integrating it into a multimodal transportation 

center. For example, BWI Airport operates a free passenger shuttle 

between the nearby Amtrak station and the airport terminal, at a cost of 

$2 million per year. In addition to the shuttle service, the Maryland Transit 

Administration has used $9 million from the HSIPR grant program to 

make BWI Airport Amtrak station improvements, including planning for 

track and rail station upgrades. In contrast, the development of the Miami 

Intermodal Center—which includes construction of a rail station 

collocating Amtrak, commuter rail, and heavy rail transit access at Miami 

International Airport, a rental car facility, and an automated people 

 43European Commission, Roadmap to a Single European Transport Area - Towards a 

Competitive and Resource Efficient Transport System, COM (2011) 144 final (Brussels, 

BD: Mar. 28, 2011).

44Massimiliano Zanin, Ricardo Herranz, and Sophie Ladousse, “Environmental benefits of 

air–rail intermodality: The example of Madrid Barajas,” Transportation Research Part E 48 

(2012). Paul Chiambaretto, Christopher Decker, “Air-rail Intermodal Agreements: 

Balancing the Competition and Environmental Effects,” Journal of Air Transport 

Management 23 (2012). 

45Anthony Perl and John Calimente, “Integrating High-Speed Rail into North America’s 

Next Mobility Transition,” Environmental Practice, Vol 13 (2011).

46See for example, Wolfgang G. Grimme, “Air/Rail Passenger Intermodality Concepts in 

Germany,” World Review of Intermodal Transportation Research, vol. 1, no. 3 (2007). 

Costs
Page 22 GAO-13-691 Intermodal Transportation

mover—is estimated to cost approximately $2 billion. Depending upon the 

scope of new infrastructure, project costs may include constructing 

stations, structures, signal systems, power systems, and maintenance 

facilities; relocating utilities; and obtaining rights-of-way, among other 

things. In addition to infrastructure costs, on-going operation and 

maintenance costs can be high for states and local transportation 

agencies. For example, airport officials estimate that the automated 

people mover system that connects Newark Liberty International Airport 

and the nearby Amtrak station costs $26 million per year to operate and 

maintain. Furthermore, PRIIA requires that operating and capital costs be 

allocated among the states and Amtrak in connection with the operation 

of certain Amtrak routes.47 Absorbing such costs could be challenging for 

states and localities as they continue to face near-term and long-term 

fiscal challenges resulting from increasing gaps between revenue and 

expenditures.48

Table 2: Projected Construction Costs of Selected Ongoing Projects to Expand Air-Rail Connectivity

Description Location

Projected cost 

($ in millions) Funding source(s)

Targeted 

completion

Miami Intermodal Center including 

construction of a rental car facility, 

intercity passenger rail station, 

automated people mover, and local 

transit connection to existing 

Metrorail system at the airport

Miami International 

Airport, Miami, FL

$2,023 • Federal funding (Transportation 

Infrastructure Finance and 

Innovation Act loans)

• State funding (Florida Department 

of Transportation loans)

• Local funding (Miami-Dade County 

contributions)

• Other funding (rental car customer 

facility charges, toll road revenue) a

2014

 47Pub. L. No. 110-432, div. B, title II, § 209, 122 Stat. 4848, 4907, 4917-4918. The routes 

include high-speed rail corridors designated by the Secretary of Transportation (other than 

the Northeast Corridor railroad line, which extends from Boston, Massachusetts, to 

Washington, D.C.); short-distance corridors and routes currently part of the national rail 

passenger transportation system that do not exceed 750 miles between their endpoints; 

and intercity rail routes not included in the national rail passenger transportation system 

that Amtrak operates on behalf of state or local entities.

48GAO, State and Local Governments’ Fiscal Outlook April 2013 Update, GAO-13-546SP 

(Washington, D.C.: Apr. 29, 2013).
Page 23 GAO-13-691 Intermodal Transportation

Description Location

Projected cost 

($ in millions) Funding source(s)

Targeted 

completion

Regional Intermodal Transportation 

Center, which will connect the 

airport to the existing Amtrak 

station and include a commuter rail 

link

Bob Hope Airport, 

Burbank, CA

$112 • Federal funding (Federal Transit 

Administration and Federal 

Highway Administration grants)

• Passenger facility charges

• Other funding (rental car customer 

facility charges)

2014

Baltimore/Washington International 

Thurgood Marshall (BWI) Airport 

Amtrak station improvements, 

including planning for track and rail 

station upgrades

BWI Airport, 

Baltimore, MD

$9 • Federal funding (High Speed 

Intercity Passenger Rail grants)

2014

Source: GAO analysis of state DOT and airport data.

a

The amount of private sector funds for this project are to be determined.

In addition to the direct financial costs of constructing, operating, and 

maintaining air-rail connections, economic costs may arise due to impacts 

on other transportation modes. For example, representatives from the 

Association of American Railroads noted that there is limited additional 

capacity on the freight rail lines shared between Amtrak and the freight 

railroads.49

 49The Association of American Railroads is a trade association whose membership 

includes freight railroads that operate 82 percent of the line-haul mileage, employ 95 

percent of the workers, and account for 97 percent of the freight revenue of all railroads in 

the United States, and passenger railroads that operate intercity passenger trains and 

provide commuter rail service.

Accordingly, these representatives stated that any additional 

intercity passenger traffic initiated to enhance air-rail connectivity on 

existing freight rail lines could increase the cost and reduce the timeliness 

of freight shipped on these lines. In such an event, Amtrak and the freight 

railroads may have to revisit agreements over the usage of the freight rail 

lines, which can be a lengthy and costly process for all stakeholders. 

Alternatively, Amtrak or other intercity passenger rail service operators 

may need to acquire additional right-of-way and construct additional 

tracks to accommodate increased connectivity between airports and 

intercity passenger rail, which, as discussed previously, could increase 

the cost of providing air-rail connectivity. Similarly, representatives from 

two of the four airlines we interviewed stated that developing intercity 

passenger rail service that provides an alternative to air travel could affect 

their profitability.
Page 24 GAO-13-691 Intermodal Transportation

As with many large capital projects, committing financial resources for airrail projects may also impose opportunity costs as a result of delaying or 

deferring other projects or initiatives. Specifically, the financial cost of airrail connectivity projects could affect the ability of governmental entities to 

pursue other types of transportation projects, particularly in the current 

fiscal environment. For example, one airline representative we 

interviewed noted that air travel is in direct competition for resources with 

other modes of transportation and suggested that any federal funds 

provided to enhance air-rail connectivity could come at the expense of 

funding for other programs, including the Next Generation Air 

Transportation System (NextGen) air traffic control modernization 

initiative.50

Given the high potential costs of air-rail connections, it is likely that only a 

limited number of places could demonstrate potential benefits high 

enough to justify improved air-rail connectivity investments. For example, 

if air passengers could access a nationwide rail network directly at an 

airport, some passengers might travel to that airport from other cities by 

train rather than on highways or short-haul flights, which might reduce 

highway or airport and aviation congestion. However, the demand for 

such service is likely to be low except in a few highly congested travel 

corridors, such as the Northeast Corridor, where the distances are short 

enough to make rail travel times competitive with air travel times. At 

airports that do not have substantial highway or airport congestion, such 

benefits would not be realized. There might still be some emission and 

energy benefits, but since the number of travelers likely to use these 

facilities at such airports is limited, these benefits will be limited as well.

Amtrak officials noted that costs and benefits are relative to the scope 

and complexity of each air-rail connectivity option. For example, they 

noted that providing an air-rail connection that serves both intercity and 

local commuter rail, such as those provided by many of Amtrak’s airportadjacent stations, can provide benefits that might not be justified if the 

station was served only by intercity rail. Furthermore, Amtrak officials 

noted that exploring air-rail integration early during the planning and 

development of an airport can help reduce the overall cost of developing 

air-rail connectivity, while still achieving substantial mobility benefits.

 50NextGen is FAA’s initiative to transform the nation’s existing ground-based air-traffic 

control system to an air-traffic management system using satellite-based navigation and 

other advanced technology. FAA estimates that NextGen improvements through 2030 

may cost approximately $37 billion. 
Page 25 GAO-13-691 Intermodal Transportation

Based on input from our expert survey; discussions with stakeholders, 

including state departments of transportation, local transportation 

planning organizations, airports, and airlines; and our review of academic 

literature, we identified five categories of factors that can greatly affect airrail connectivity, including the degree of leadership and collaboration 

among stakeholders, resource availability, the extent of passenger 

demand for air-rail connectivity, the ease of the air-rail connection, and 

the passenger rail service operating characteristics.51

Table 3: Factors Surveyed Experts Most Frequently Cited As Greatly Facilitating and Greatly Hindering Air-Rail Connectivity

(See table 3.)

Category Factors that facilitate Factors that hinder

Leadership/

stakeholder collaboration

• Integration of air-rail connections into an 

overall, multi-modal transportation 

plan/strategy

• Communication, collaboration, and 

consensus across stakeholders, including, 

local, state, federal, and private sector 

entities

• Lack of integration of air-rail connections into an 

overall, multi-modal transportation plan or strategy

• Lack of leadership for air-rail project or leadership 

is diffused across many stakeholders

Resource availability • Available funding for air-rail connectivity 

projects

• The financial cost of air-rail connectivity projects

• Lack of dedicated funding for air-rail connectivity 

projects

• Lack of existing intercity passenger rail 

infrastructure, including tracks and stations

• Lack of available right-of-way, land, or other 

physical space for air-rail projects

Passenger demand • Sufficient passenger demand for intercity 

passenger rail service

• Lack of demand for intercity passenger rail service 

to the airport

Ease of connection • Close proximity between airport and 

intercity passenger rail station

• Ease of use of the airport-rail connections

• Availability of information, including signage, 

provided to make the connection between 

the airport and rail service

• Lack of close proximity between airport and 

intercity passenger rail station

 51In our survey, experts rated factors that were identified by other experts as either 

facilitating or hindering air-rail connectivity. For factors identified as facilitating air-rail 

connectivity, experts rated each factor as “greatly facilitates,” “facilitates,” “somewhat 

facilitates,” “does not facilitate,” “not a factor,” or that they had “no opinion.” Similarly, for 

factors that were identified by experts to hinder air-rail connectivity, experts rated each 

factor as “greatly hinders,” “hinders,” “somewhat hinders,” “does not hinder,” “not a factor,”

or that they had “no opinion.” For more information on our survey and results, see 

appendix I and GAO-13-692SP, respectively. 

Air-Rail Connectivity 

Is Influenced by a 

Variety of Factors
Page 26 GAO-13-691 Intermodal Transportation

Category Factors that facilitate Factors that hinder

Rail service operating 

characteristics

• Frequent intercity passenger rail service

• Reliable intercity passenger rail service that 

departs and arrives on schedule

• High-speed intercity passenger rail service 

connects to the airport

• Lack of frequent intercity passenger rail service

• Lack of reliable intercity passenger rail service

Source: GAO analysis.

Note: We identified these factors based on the number of experts rating that a given factor “greatly 

facilitates” or “greatly hinders” the development and use of air-rail connectivity.

The degree of leadership and the extent of stakeholder collaboration 

across air-rail projects can affect project development. Specifically, 

almost half of the experts (18 of 40) rated the lack of leadership as greatly 

hindering air-rail connections. Stakeholders we interviewed during our site 

visits told us that when there is an absence of leadership, stakeholders 

are unlikely to assume roles outside of their typical responsibilities and 

interests, a limitation that makes project development more difficult.

Conversely, leadership that helps build bridges across stakeholder 

groups can help develop a shared vision and foster collaboration, thereby 

facilitating project development.

However, we found there is limited federal leadership for air-rail projects, 

and no modal administration has a primary responsibility to oversee airrail projects, as responsibilities for transportation projects are segmented 

by mode. Furthermore, according to an academic study and stakeholders 

we interviewed, the United States is lacking a national policy framework 

and vision to guide investment in the needed infrastructure to develop airrail connections.52 For example, FRA’s High-Speed Rail Strategic Plan 

does not address connectivity between airports and intercity passenger 

rail.53 In addition, while DOT’s 2012-2016 strategic plan broadly discusses 

connectivity between airports and intercity passenger rail, DOT has not 

established any specific goals for air-rail connectivity.54

 52Anthony Perl and John Calimente, “Integrating High-Speed Rail into North America’s 

Next Mobility Transition,” Environmental Practice, Vol. 13 (2011).

This is consistent 

with our previous work that concluded that the absence of specific 

53Department of Transportation, Vision for High-Speed Rail in America (Washington, D.C.:

April 2009).

54Department of Transportation, Transportation for a New Generation:Strategic Plan for 

Fiscal Year 2012-16. 

Leadership and 

Stakeholder Collaboration
Page 27 GAO-13-691 Intermodal Transportation

national goals to develop intermodal capabilities at airports is a significant 

barrier to developing air-rail connections.55 For example, half of the 

experts (20 of 40) rated integration of air-rail connections into an overall, 

multi-modal transportation plan or strategy as an approach that would 

greatly facilitate air-rail connectivity in the United States. In addition, 

officials we interviewed and over half of the experts (23 of 39) said that 

communication, collaboration, and consensus among stakeholders such 

as airlines; rail operators; airport management; and local, state, and 

federal government officials could greatly facilitate air-rail connectivity.

Resource availability, including funding, right-of-way, and access to 

existing infrastructure can greatly affect the development of air-rail 

connectivity. As previously noted, the costs of linking existing intercity 

passenger rail infrastructure and airports can be significant, depending in 

part on the complexity and scope of the project. Slightly over half of the 

experts (21 of 40) rated the financial cost of a project as greatly hindering 

project development, while nearly three-fourths (29 of 40) rated 

availability of funding as greatly facilitating project development. In 

addition, about two-fifths of the experts (16 of 39) rated the level of 

funding for intercity passenger rail as a very important factor contributing 

to differences in air-rail connectivity development and use between the 

United States and Europe.

We found a number of barriers exist to securing funding for air-rail 

connectivity projects. For example, transportation officials and 

stakeholders we interviewed told us that the limitations on use of funds 

from federal grants and airport revenue collected from passenger facility 

charges are significant barriers. Furthermore, as noted previously in this 

report, the federal government does not provide funding dedicated to the 

development or operation of air-rail connections. If the trend of 

decreasing federal transportation funding over the past three decades 

continues, air-rail project sponsors may need to increasingly rely on state 

funds for air-rail connection projects.56 In addition, our prior work also 

identified challenges of funding intercity passenger rail projects.57

 55

The 

GAO-05-727.

56GAO, Grants to State and Local Governments: An Overview of Federal Funding Levels 

and Selected Challenges, GAO-12-1016 (Washington, D.C.: Sept. 25, 2012).

57GAO, High- Risk Series: An Update, GAO-13-283 (Washington, D.C.: February 2013). 

Resource Availability
Page 28 GAO-13-691 Intermodal Transportation

federal government has recently begun to pursue investment in highspeed passenger rail through the FRA’s HSIPR grant program, and to 

date has obligated about $9.9 billion for 150 high-speed and intercity 

passenger rail projects from funds appropriated in fiscal years 2009 and 

2010—with more than one-third of the amount obligated designated for 

the high-speed rail project in California. While this funding will allow many 

projects to begin construction, it is not sufficient to complete them.

Furthermore, Congress has not appropriated any funding for the HSIPR 

program since fiscal year 2010.

The availability of other resources can also greatly affect the development 

of air-rail connectivity projects. Three-fifths of the experts (24 of 40) rated 

the lack of availability of land or physical space for direct air-rail projects, 

including the lack of existing intercity passenger rail infrastructure (e.g., 

tracks and stations) and rights of way, as factors that greatly influence the 

development of air-rail connections.

Passenger demand for air-rail connectivity has a significant role in 

developing and using such connections. Approximately half of the experts 

rated passenger volume and demand as a factor that can either greatly 

facilitate (if sufficient) (21 of 39) or hinder (if lacking) (20 of 40) air-rail 

connectivity projects. However, as mentioned previously in this report, 

there is limited data on the demand for intercity passenger rail.

Furthermore, it is often difficult to estimate ridership demand. As we have 

previously reported, limited data and information, especially early in a 

project before specific service characteristics are known, make 

developing reliable ridership demand forecasts difficult.58 Research on 

ridership forecasts for rail infrastructure projects around the world have 

shown that ridership forecasts are often overestimated.59 Furthermore, 

there are no industry standard or established criteria for developing or 

evaluating intercity passenger and high-speed rail ridership forecasts.60

Over three-quarters of the experts (31 of 40) rated close proximity 

between the airport terminals and rail stations as greatly facilitating air-rail 

 58GAO, High-Speed Passenger Rail: Preliminary Assessment of California’s Cost 

Estimates and Other Challenges, GAO-13-163T (Washington, D.C.: Dec. 6, 2012).

59GAO-13-304.

60GAO-13-304. 

Passenger Demand

Ease of Connection
Page 29 GAO-13-691 Intermodal Transportation

connectivity.61 Connections that are easy to use and provide direct 

connection between the airport terminal and the rail station can greatly 

affect the development of air-rail connectivity. Officials we interviewed 

noted that air-rail connections should be designed to meet the needs of 

airport and intercity passenger users. Accordingly, they underscored that 

connections should be designed to make the experience as easy and 

seamless as possible for the traveler. Similarly, over half of the experts 

(21 of 39) rated the availability of information, including signage, about a 

connection as greatly facilitating air-rail connectivity. We found 20 of the 

60 major airports in the contiguous United States included information 

about Amtrak on their respective websites, and 14 of the 20 airports 

provided specific instructions on how passengers could connect to or 

from Amtrak.62

Nearly two-thirds of the experts (26 of 40) and many of the stakeholders 

at our site visits cited frequency and reliability of rail service as factors 

that greatly influence air-rail connectivity. Stakeholders we interviewed 

noted that for the air-rail connection to be viable, the passenger rail 

operator needs to provide frequent service to multiple locations beyond 

the airport. The frequency of Amtrak service is highly variable across the 

nation. Similarly, a number of stakeholders we spoke with noted that the 

reliability of Amtrak service, specifically its on-time performance, affects 

the use of intercity passenger rail for travel, both between cities and to 

and from the airport. In addition, over half of the experts (25 of 40) rated 

the availability of high-speed intercity passenger rail service to connect to 

an airport as greatly facilitating an air-rail connectivity project. However, 

representatives from three of the four airlines we interviewed viewed highspeed rail as a potential competitor in diverting passengers away from, as 

opposed to feeding into, the airport.

 61Approximately the same number of experts rated the lack of close proximity as a factor 

that greatly hindered air-rail project development.

62Based on a review of 60 major airports’ ground transportation pages on their websites in 

April 2013.

Rail Service Operating 

Characteristics
Page 30 GAO-13-691 Intermodal Transportation

Experts participating in our survey suggested five key areas where 

implementing strategies could help improve air-rail connectivity: vision, 

coordinated planning, funding, infrastructure, and awareness and 

marketing of connections. We asked these experts to identify potential 

strategies, and then rate these strategies in terms of both their 

importance and their feasibility. Some of the strategies that experts rated 

as more important were also seen as less feasible.63

Table 4: Experts’ Rating of Importance and Feasibility of Selected Strategies to Improve Air-Rail Connectivity

(See table 4.) In 

discussing these strategies with other stakeholders and reviewing 

academic studies, we found that a number of strategies were interrelated. For example, some of the strategies that experts suggested to 

improve connectivity, such as increasing connections with other 

transportation modes, could be related to the implementation of other 

strategies, such as providing additional funding for air-rail connections.

More feasible Less feasible

More important • Conduct additional study of air-rail policies in other 

countries as well as potential air-rail locations and 

ridership preferences in the United States

• Ease restrictions on using funds collected through 

passenger facility charges

• Include air-rail connections to the airport when 

intercity passenger rail service is first established in 

a corridor

• Emphasize intermodal connectivity as a criterion for 

federal transportation funding

• Connect intercity passenger rail to other modes of 

transportation, including mass transit

• Connect intercity passenger rail to city centers and 

urban attractions

• Permit greater flexibility in using federal 

transportation grant funding

• Provide dedicated funding for air-rail connections

• Integrate existing rail service with airports, locating 

terminal as close to rail station as possible

• Provide additional funding for intercity passenger rail

• Alignment of long-term transportation plans across 

modes

 63Experts in our survey identified and rated 34 strategies. When rating the importance of a 

potential strategy, experts were asked to rate the strategy as either “very important,”

“important,” “somewhat important,” “not important,” or that they had “no opinion.” Similarly, 

experts were asked to rate the feasibility of a strategy as “very feasible,” “feasible,”

“somewhat feasible,” “not feasible,” or that they had “no opinion.” For a full accounting of 

our results, please see GAO-13-692SP.

Strategies to Improve 

Air-Rail Connectivity 

May Require 

Substantial 

Coordination and 

Funding
Page 31 GAO-13-691 Intermodal Transportation

More feasible Less feasible

Less important • Provide additional federal guidance on air-rail 

projects

• Develop business cases to support air-rail 

connections

• Establish national goals for air-rail connectivity

• Emphasize intermodal connectivity as a core federal 

planning requirement

• Establish a national framework for intermodal 

collaboration

• Align intercity passenger rail schedules with airline 

schedules

• Establish a federal entity to work across modal 

administrations to champion intermodal and air-rail 

projects

• Incentivize public-private partnerships to help fund 

and construct air-rail projects

Source: GAO analysis.

Note: We identified a strategy as “more important” if that strategy was within the top 10 strategies 

most frequently rated by experts as “very important,” including ties. Similarly, we identified a strategy 

as “more feasible” if the strategy was within the top 10 strategies most frequently rated by experts as 

“very feasible,” including ties. Strategies outside the top ten most frequently cited as very important 

and very feasible were classified as “less important” and “less feasible,” respectively. This table does 

not list all of the strategies that were both “less important” and “less feasible.” For full details on the 

results of our survey, see GAO-13-692SP.

Experts stated additional study of the demand for air-rail connectivity, as 

well as lessons learned in other countries, could help Amtrak and DOT 

clarify needs and develop priorities within their existing goals related to 

enhancing connectivity. Connectivity across modes has been emphasized 

broadly by DOT and Amtrak, though there has been limited emphasis 

placed by either for connectivity between airports and intercity passenger 

rail. For example, in its 2012-2016 strategic plan, DOT’s goal of 

encouraging livable communities emphasizes connectivity across modes, 

and identifies connectivity between intercity passenger rail and transit and 

continued investment in the intercity passenger rail network as means to 

achieve that goal. DOT’s strategic plan also notes that DOT will continue 

to work with Amtrak, states, freight railroads, airports, and other key 

stakeholders to ensure intercity passenger rail is effectively integrated 

into the national transportation system, though the department has not 

established any specific goals for air-rail connectivity. Similarly, DOT’s 

most recent update to its national rail plan, published in September 2010, 

encourages the integration of policies and investments across modes, 

including air transportation, to provide convenient options for accessing 

the passenger rail network, but does not establish specific goals or 

timelines for increasing air-rail connectivity. Amtrak’s strategic plan has 

set a goal of connecting to three additional airports in the Northeast 

Corridor by 2015 as part of its efforts to increase intercity passenger rail 

connectivity with other travel modes in key markets, but Amtrak officials 

we spoke with stated that they do not believe Amtrak will achieve this 

goal because of limited available funding for intercity passenger rail.

Study of Preferences and 

Demand for National 

Priorities
Page 32 GAO-13-691 Intermodal Transportation

Should DOT, Amtrak, or Congress choose to develop a more 

comprehensive approach to air-rail connectivity, experts we surveyed 

identified further study of passenger preferences and demand as one of 

the most important and most feasible steps policymakers could take to 

improve air-rail connections. For example, half of the experts (20 of 40) 

rated additional study of ridership preferences across all modes as very 

important to informing the federal government’s air-rail strategy. As 

previously noted, limited data on passenger preferences and demand for 

air-rail connectivity exists. For example, one expert emphasized that 

because passenger demand for air-rail connectivity varies across the 

country, additional study of passenger preferences at the local level could 

help identify approaches tailored to the specific needs of the area, noting 

that there is no “one size fits all” approach to air-rail connectivity.

Furthermore, 24 of 40 experts rated studying lessons learned and policy 

responses from other countries as “very important” toward improving 

understanding of air-rail connectivity issues, though as previously 

discussed, air-rail connectivity approaches vary widely outside the United 

States.

Experts in our survey and stakeholders at seven of our eight site visits 

highlighted the importance of coordinated transportation planning 

between airports and intercity passenger rail, which could help 

stakeholders develop multimodal solutions and facilitate problem solving.

Amtrak officials noted that if airports, Amtrak, and other transportation 

stakeholders begin to plan for integration early, the costs of connecting air 

and rail transportation become part of a larger intermodal strategy and 

can provide benefits. Accordingly, both Amtrak officials and experts 

highlighted the importance of planning an intercity passenger rail 

connection as part of an overall ground access strategy. For example, 17 

of 40 experts rated planning air-rail connections to the airport during the 

initial establishment of intercity passenger rail service as very important.

Amtrak officials noted that planning for intercity rail connections at airports 

during the initial development of the airport can help minimize the 

incremental cost of making a connection while providing substantial 

benefits from air-rail connectivity. However, in many locations, particularly 

in the Northeast Corridor, the rail network was developed decades before 

the airport. In addition, such an approach may not be feasible, as federal 

funding and oversight is segmented by mode, a segmentation that can 

lead to competition, rather than collaboration for funding. Furthermore, 

collaboration across stakeholder groups can be a time-intensive process 

and may not necessarily change the willingness of stakeholders to 

collaborate.

Collaborative Planning
Page 33 GAO-13-691 Intermodal Transportation

Experts we surveyed and stakeholders at six of our eight site visits we 

interviewed highlighted the importance of securing funding for air-rail 

connectivity projects. Because of the often substantial cost of the physical 

infrastructure to support air-rail connections, stakeholders at four of our 

eight site visits noted that the federal government may have to provide 

most of the funding to make development possible. Over half of the 

experts in our survey (22 of 41) as well as other stakeholders at five of 

our eight site visits suggested that dedicated funding for air-rail 

connections could help increase the number of connections between 

airports and intercity passenger rail. Alternatively, nearly half (17 of 41) of 

the experts in our survey suggested that increased funding for intercity 

passenger rail is a very important strategy related to increasing Amtrak’s 

ability to connect to airports. However, the current fiscal environment 

presents challenges to increasing federal funding for discretionary 

programs though some existing grant and loan programs—such as the 

HSIPR, Transportation Investment Generating Economic Recovery 

(TIGER), and Transportation Infrastructure Finance and Innovation Act of 

1998 (TIFIA) programs—have some flexibility to fund air-rail connections 

if such a connection is a state or local priority.64

Stakeholders at four of our eight site visits also suggested that providing 

additional flexibility in permitted expenditures among existing federal 

programs could help improve airport connectivity via rail. In particular, 

they suggested changes to the airport passenger facility charge authority 

as well as to the AIP grant program. Among the funding strategies 

evaluated in our expert survey, experts generally rated the strategy of 

relaxing the restrictions on passenger facility charges among the most 

As previously noted, 

additional funding for air-rail connections could require tradeoffs with 

other transportation projects. With limited existing funds available for airrail projects, two stakeholders we interviewed suggested that the federal 

government should focus on a few air-rail projects of national

significance, rather than a number of smaller projects throughout the 

entire nation. Similarly, one stakeholder suggested that the federal 

government provide money for a few projects to demonstrate the potential 

benefits of air-rail connectivity, before moving forward on a nationwide 

program.

 64For more information on these and other selected programs that may be used to fund 

and finance air-rail connectivity, see appendix III. 

Funding and Flexibility
Page 34 GAO-13-691 Intermodal Transportation

feasible strategies. Airport operators may currently use funds collected 

from air passengers through passenger facility charges to fund rail access 

at airports, if the project is owned by the airport, located on airport 

property, and used exclusively by airport passengers and employees.

However, easing these restrictions on use of passenger facility charges 

faces obstacles. Specifically, use of passenger facility charge revenues is 

limited by law to airport-related projects. Such a change would require 

legislative action by the Congress, and changes to the passenger facility 

charges program have been opposed by the airline industry. For 

example, representatives from one airline we spoke with stated that the 

airline was fundamentally opposed to using funds collected through 

passenger facility charges to pay for airport and intercity passenger rail 

connections because, in their view, the federal government should not tax 

airline passengers to fund other transportation modes. Stakeholders at 

three of the eight airports we spoke with suggested that Congress could 

allow additional flexibility in the use of funds from transportation grant 

programs, including the AIP program, which is funded through a variety of 

aviation excise taxes. While AIP grants may currently be used to fund 

projects promoting air-rail connectivity on the airport property, like the 

passenger facility charges, program funds may only be used to fund 

airport-related projects. Again, however, airlines we spoke with opposed 

easing existing limitations on the use of AIP grants for airport projects that 

may benefit non-aviation passengers, and any change to the AIP program 

to broaden the use of these grants would require congressional action.

Furthermore, as previously noted, the commitment of financial resources 

for air-rail projects may also impose opportunity costs as a result of 

canceling or delaying other projects or initiatives that could be funded by 

these federal programs.

Experts in our survey suggested that increasing the size and operation of 

the existing intercity passenger rail network could help encourage the 

development and use of intercity passenger rail to access airports.

Specifically, 23 of 39 experts cited the size and the extent of the intercity 

passenger rail network as a very important factor resulting in differences 

between air-rail connections in the United States and Europe.

Accordingly, over two-thirds of the experts in our survey (27 of 40) 

suggested that developing rail connections to transit and other forms of 

public transportation could help encourage the use of rail to the airport, 

and over half of the experts (22 of 40) stated that additional connections 

to city centers and urban attractions are very important strategies to 

consider. DOT has taken some steps to increase the intercity passenger 

rail network, most notably through the HSIPR grant program, which, FRA 

Infrastructure Connectivity
Page 35 GAO-13-691 Intermodal Transportation

officials noted, placed emphasis on using funds available for intercity 

passenger rail infrastructure to establish and enhance connections 

between major metropolitan areas. Additionally, stakeholders we 

interviewed at six of our eight sites noted that increasing the frequency of 

intercity passenger service in existing corridors could encourage greater 

use of rail to connect to the airport. For example, one stakeholder noted 

that passengers are much less likely to use rail if departure times are 

hours apart, as opposed to minutes. However, even in corridors that have 

existing intercity passenger rail service, increasing the frequency of 

service can be challenging due to both the cost and, as previously 

discussed, the shared usage of the infrastructure with the freight 

railroads. Furthermore, as discussed previously, stakeholders we spoke 

with stated that there is limited demand for public transportation options to 

connect to the airport, and thus it is unclear whether increasing the 

frequency of service will increase passenger use of intercity rail service to 

connect to airports.

While building the infrastructure to support new air-rail connections can 

be expensive and time-intensive, our work identified a few low cost 

options that could help increase passenger awareness, and thus usage, 

of existing air-rail connections. For example, Amtrak station operators and 

airport officials could take steps to increase awareness of existing 

connections between the two modes, using additional or more 

prominently placed signage and information kiosks. For example, at the 

BWI Airport Amtrak Station, signs and information direct customers 

exiting the station platform to the bus shuttle service connecting the two 

modes. (See fig. 3.) Similarly, in Burbank, officials stated that the use of 

signage highlighting the walking path between the Burbank rail station 

and the airport has helped, in part, to make the connection between the 

two modes easier for passengers to use. These officials also noted that 

even with signage, an air-rail connection often required frequent and 

reliable service from an intercity passenger rail operator. As another 

option, Amtrak could highlight the connections to the airport from each 

station on its website, thus providing an additional source of information 

to travelers beyond what is available at the airport or rail station.

Awareness of Air-Rail 

Connections
Page 36 GAO-13-691 Intermodal Transportation

Figure 3: Signage and Information at the BWI Airport Amtrak Station

We provided a draft of this product to DOT and Amtrak for comment. DOT 

and Amtrak provided technical comments on the draft, which we 

incorporated as appropriate. DOT and Amtrak did not have any 

comments on the e-supplement.

We are sending copies of this report to the Secretary of Transportation, 

the President of Amtrak, and the appropriate congressional committees.

In addition, this report will be available at no charge on the GAO website 

at http://www.gao.gov.

If you have any questions about this report, please contact me at (202) 

512-2834 or dillinghamg@gao.gov. Contact points for our Offices of 

Congressional Relations and Public Affairs may be found on the last page 

Agency Comments
Page 37 GAO-13-691 Intermodal Transportation

of this report. GAO staff who made key contributions to this report are 

listed in appendix V.

Gerald L. Dillingham, Ph.D

Director

Physical Infrastructure Issues
Appendix I: Objectives, Scope, and 

Methodology

Page 38 GAO-13-691 Intermodal Transportation

This report addressed the following objectives: (1) the nature and scope 

of existing air-rail connectivity in the United States; (2) the benefits and 

costs of developing air-rail connectivity; (3) the factors that facilitate and 

hinder the development and use of air-rail connectivity; and (4) potential 

strategies, including lessons learned from other countries, that may help 

inform deliberations regarding air-rail connectivity policy. This report 

focused on air-rail connections between an airport terminal and an 

intercity passenger rail station. In other contexts, an air-rail connection 

may refer to a connection between an airport terminal and an intracity rail 

station that serves other forms of local rail, such as commuter rail or a 

subway system.

To address our objectives, we obtained and analyzed information from a 

variety of sources. We reviewed and synthesized information from our 

body of work and relevant academic literature on intermodal 

transportation, air-rail connectivity, and air-rail code share agreements in 

the United States and internationally. We reviewed citations identified 

through a search of databases containing peer-reviewed articles, 

government reports, and “gray literature,” including Transport Research 

International Documentation, Social SciSearch, and WorldCat.1

 1

“Gray literature” publications may include, but are not limited to, the following types of 

materials: reports (pre-prints, preliminary progress and advanced reports, technical 

reports, statistical reports, memorandums, state-of-the art reports, market research 

reports, etc.), theses, conference proceedings, technical specifications and standards, 

non-commercial translations, bibliographies, technical and commercial documentation, 

and official documents not published commercially (primarily government reports and 

documents).

Publications were limited to the years 2004 through 2012. After an initial 

review of citations, 48 articles were selected for further review. To collect 

information on the articles, we developed a data collection instrument to 

gather information on the articles’ scope and purpose, methods, findings, 

and their limitations, and additional areas for follow-up, including a review 

of the bibliography to determine the completeness of our literature search.

To apply this data collection instrument, one analyst reviewed each article 

and recorded information in the data collection instrument. A second 

analyst then reviewed each completed data collection instrument to verify 

the accuracy of the information recorded. We summarized the findings 

and limitations of the articles based on the completed data collection 

instruments, as well as areas for additional research identified in the 

articles. In addition, we also reviewed federal laws related to air and 

Appendix I: Objectives, Scope, and 

Methodology
Appendix I: Objectives, Scope, and 

Methodology

Page 39 GAO-13-691 Intermodal Transportation

intercity passenger transportation and strategic plans from Amtrak and 

the Department of Transportation (DOT).

We interviewed officials from DOT and Amtrak, transportation experts, 

and representatives from U.S. airlines and industry associations to obtain 

their perspectives on air-rail connectivity issues. We reviewed completed, 

ongoing, and future air-rail connectivity efforts at eight airports in the 

United States, and interviewed a variety of stakeholders at each site, 

including airport authorities, state and local transportation agencies, local 

transportation planning organizations, and air and rail industry 

associations. (See table 5.) These airports were selected to include 

airports that have recently planned, constructed, or completed an air-rail 

project and are dispersed in various regions of the country. Our findings 

at these sites were selected as part of a judgmental, non-probability 

sample of air-rail connectivity efforts at airports, and cannot be 

generalized to all airports.

Table 5: Airports and Stakeholders Selected for GAO Review 

Airport Geographic location Stakeholders

Baltimore/Washington International 

Thurgood Marshall

Glen Burnie, MD • Maryland Aviation Administration

• Maryland Department of Transportation

• Maryland Transit Administration

Bob Hope Burbank, CA • Bob Hope Burbank Airport Authority

• California Department of Transportation

• Southern California Association of Governments

Chicago O’Hare International Chicago, IL • Chicago Department of Aviation

• Illinois Department of Transportation

• Chicago Department of Transportation

• Chicago Metropolitan Agency for Planning

• Midwest High Speed Rail Association

Dallas/Fort Worth International Fort Worth, TX • Dallas/ Fort Worth Airport

• Texas Department of Transportation

• North Central Texas Council of Governments

• Dallas Area Rapid Transit

Miami International Miami, FL • Miami-Dade Aviation Department

• Florida Department of Transportation

• Miami-Dade County Municipal Planning Organization

• Miami-Dade Transit
Appendix I: Objectives, Scope, and 

Methodology

Page 40 GAO-13-691 Intermodal Transportation

Airport Geographic location Stakeholders

General Mitchell International Milwaukee, WI • Milwaukee General Mitchell International Airport

• Wisconsin Department of Transportation

• Southeastern Wisconsin Regional Planning Commission

• Airport Gateway Business Association/Gateway to 

Milwaukee

Norman Y. Mineta San Jose International San Jose, CA • San Jose International Airport

• City of San Jose Department of Transportation

• Metropolitan Transportation Commission 

Newark Liberty International Newark, NJ • The Port Authority of New York and New Jersey

• Regional Plan Association

• New Jersey Transit

Source: GAO.

We also analyzed Amtrak’s distance and connectivity to the 28 large and 

32 medium hub airports located in the contiguous United States based on 

the 2011 Federal Aviation Administration’s Air Carrier Activity Information 

System database.2

 2

Airport hub size categories are based on the number of passengers boarding an aircraft 

(enplaned) for all operations of U.S. carriers in the United States. A large hub commercial 

service airport has 1 percent or more of total annual passenger boarding. A medium hub 

commercial service airport has at least 0.25 percent but less than 1 percent of total annual 

passenger boarding.

We limited our analysis to these 60 airports because 

they accounted for approximately 86 percent of U.S. passenger 

enplanements for calendar year 2011. We determined the linear distance 

for each of the 60 airports and the nearest Amtrak station based on 

information from the Bureau of Transportation Statistics and the National 

Transportation Atlas Database for 2012. Based on the use of both as 

widely accepted federal statistical data sources, we determined these 

data to be generally reliable for our purpose, which was to provide context 

on existing air-rail connectivity. Linear distance is the distance measured 

between two points using their latitude and longitude. This may 

understate the distance a passenger may have to travel because it does 

not account for actual travel routes (e.g., a route that crosses a bridge or 

avoids buildings or other obstacles along the passenger’s route). The 

actual distance that a passenger may travel also depends on the selected 

transportation mode, local roads, or route selected. We used the linear 

distance calculations to determine the number of airports with an Amtrak 

station within 5, 10, 20, and over 20 miles. (See app. IV.) To determine 

the modal connectivity between airport and Amtrak stations, we 
Appendix I: Objectives, Scope, and 

Methodology

Page 41 GAO-13-691 Intermodal Transportation

systematically reviewed the airport websites’ ground transportation page 

and Amtrak System Timetable for Winter/Spring 2013 for information on 

how passengers can access Amtrak to and from the airports.

To obtain additional insight on issues related to air-rail connectivity, we 

collaborated with the National Academy of Sciences to identify 25 experts 

from the aviation and rail industries, Amtrak, state and local governments, 

academia, and the private sector. These experts were selected based on 

their knowledge of one or more of the following topic areas:

intermodalism, airlines and the air travel industry, airport operations, the 

rail industry, and passenger travel. We identified 17 additional experts in 

these fields through a review of academic literature, our previous work, 

and interviews with stakeholders. (See app. II for a list of these experts.)

We conducted a web-based survey in which we asked these 42 experts 

for their views on the benefits of air-rail connectivity, factors that facilitate 

and hinder the development and use of air-rail connectivity, differences 

between air-rail connectivity in the United States and Europe, and 

strategies that could improve air-rail connectivity. We employed a 

modified version of the Delphi method to organize and gather these 

experts’ opinions.3

 3

The Delphi method, developed by the RAND Corporation in the 1950s, is most commonly 

applied in a group-discussion forum. We modified the approach to have the group 

discussion take place in the form of a web-based forum. 

Experts were sent an email invitation to complete the 

survey on a GAO web server using a unique username and password. 

The survey was conducted in two stages. The first stage of the survey—

which ran from January 16, 2013, to February 19, 2013—asked the 

experts to respond to five open-ended questions about various aspects of 

air-rail connectivity based on our study objectives. To encourage 

participation by our experts, we stated that responses would not be 

individually identifiable and that results would generally be provided in 

summary form. We received a 95 percent (40 of 42) response rate for the 

first stage of the survey. After the experts completed the open-ended 

questions, we performed a content analysis of the responses to identify 

the most important issues raised by our experts. Two members of our 

team independently categorized experts’ responses to each of the 

questions. Any disagreements were discussed until consensus was 

reached. We analyzed the responses provided by the experts and 

developed close-ended questions for the second stage of the survey 

where we asked each expert to evaluate the ideas and other information 

that came from the first part of the survey. Because this was not a sample 
Appendix I: Objectives, Scope, and 

Methodology

Page 42 GAO-13-691 Intermodal Transportation

survey, it had no sampling errors. However, the practical difficulties of 

conducting any survey can introduce non-sampling errors, such as 

difficulties interpreting a particular question, which can introduce 

unwanted variability into the survey results. We took steps to minimize 

non-sampling errors by pre-testing the questionnaire with 5 experts. We 

conducted pretests to help ensure that the questions were clear and 

unbiased, and that the questionnaire did not place an undue burden on 

respondents. An independent reviewer within GAO also reviewed a draft 

of the questionnaire prior to its administration. We made appropriate 

revisions to the content and format of the second survey questionnaire 

based on the pretests and independent review. The second stage of the 

survey was administered on the Internet from March 25, 2013, to May 15, 

2013. To increase the response rate, we followed up with emails and 

personal phone calls to the experts to encourage participation in our 

survey. We received responses from 41 of 42 experts, resulting in a 98 

percent response rate. The information and perspectives that we obtained 

from the expert survey may not be generalized to all experts that have an 

interest or knowledge of air-rail connectivity issues. The full survey and 

responses are available at GAO-13-692SP.

We provided a draft of this report to Matthew A. Coogan, director of the 

New England Transportation Institute for review and comment, based on 

his expertise on air-rail connectivity issues similar to those in our report. 

Mr. Coogan was selected based on his extensive past and on-going 

research on similar topics related to air-rail connectivity issues in the 

United States. He provided technical comments, which we incorporated 

as appropriate. We conducted this performance audit from August 2012 

to August 2013 in accordance with generally accepted government 

auditing standards. Those standards require that we plan and perform the 

audit to obtain sufficient, appropriate evidence to provide a reasonable 

basis for our findings and conclusions based on our audit objectives. We 

believe that the evidence obtained provides a reasonable basis for our 

findings and conclusions based on our audit objectives.
Appendix II: Experts Participating in GAO’s 

Survey on Air-Rail Connectivity

Page 43 GAO-13-691 Intermodal Transportation

Name Title Affiliation

Thomas Adler President Resource Systems Group, Inc.

Ruth Bagley Project Lead Chief Executive of Slough Borough 

Council 

John Bennett Former Assistant Vice 

President, Policy, Standards 

and Business Integration

Amtrak

Mohamed Bhanji Director, Marketing 

Technologies

VIA Rail Canada

David Classey Director, Planning and 

Programmes

Travelport

Patty Clark Senior Advisor for Aviation 

Policy

The Port Authority of New York & 

New Jersey

John Conlow Senior Director of Corridor 

Planning

Amtrak

Matthew A. 

Coogan

Director New England Transportation Institute

Linda Culp Principal Planner - Rail San Diego Association of 

Governments

Crystal DuPont Project Manager for 

Passenger Rail Planning 

Management

Wisconsin Department of 

Transportation

Dan Feger Executive Director Bob Hope Airport

Geoff Gosling Principal Aviation System Consulting

Mark Hansen Professor University of California, Berkeley

John Hansman Professor of Aeronautics 

and Astronautics

Massachusetts Institute of 

Technology

Tim Hoeffner Director Michigan Department of 

Transportation Office of Rail

Roger Hooson Senior Planner, Landside 

Operations

San Francisco International Airport

Hanan Kivett Vice President and Senior 

Project Manager, 

Transportation

AECOM

Joerg Last Managing Partner STRATA GmbH

Paul LeBlond President International Air Rail Organisation

Bob Longworth Owner Bob Longworth Consulting

William Mallett Specialist in Transportation 

Policy

Congressional Research Service

Michael Malloneea Principal Transportation 

Planner

North Central Texas Council of 

Governments

Philip Martin Head of Marketing Amadeus Rail

Appendix II: Experts Participating in GAO’s 

Survey on Air-Rail Connectivity
Appendix II: Experts Participating in GAO’s 

Survey on Air-Rail Connectivity

Page 44 GAO-13-691 Intermodal Transportation

Name Title Affiliation

Jennifer 

Moczygemba

Rail System Section Head Texas Department of Transportation

Gary Molyneaux Airport Planning Manager King County International 

Airport/Boeing Field

Curtis Morgan Program Manager Texas A&M Transportation Institute

Mike Muller Head Interline and 

Intermodal Policy

International Air Transport 

Association

Christopher Nash Research Professor Institute of Transport Studies, 

University of Leeds

Paul Neal Principal Parsons Brinckerhoff

Peter Pfragner Commissioner for 

Intermodality

Frankfurt Airport

Richard Roberts Chief Planner New Jersey Transit Corporation

Megan Smirti 

Ryerson

Assistant Professor University of Pennsylvania

John Schalliol Executive Director, Retired St. Joseph County Airport Authority

Joshua Schank President and CEO ENO Center for Transportation

George Schoener Executive Director I-95 Corridor Coalition

Andrew Sharp Policy Adviser International Air Rail Organisation

Stephen Van Beek Executive Director, Policy 

and Strategy 

LeighFisher, Inc.

Mark Walbrun Market Leader, Transit and 

Rail, East Region

CH2M Hill

Mike Welch Corporate Director of JFK 

Operations

Delta Air Lines

Joan Zatopek Senior Aviation Project 

Manager

Port of Oakland

Source: GAO.

Note: In addition to the 40 experts listed above, one official from a U.S. airline participated on the 

panel. An additional expert was selected to participate in the survey but did not provide a response in 

either round of the survey.

a

Chad Edwards and Kevin Feldt, program managers with the North Central Texas Council of 

Governments, provided input as part of this response.
Appendix III: Examples of Potential Federal 

Financing and Funding Sources for Air-Rail 

Projects

Page 45 GAO-13-691 Intermodal Transportation

Source Description

Example of use for air-rail 

projects

Airport Improvement

Program 

Provides grants to airports for planning and developing projects 

through the Federal Aviation Administration (FAA). The program is 

funded, in part, by aviation user excise taxes, which are deposited into 

the Airport and Airway Trust Fund. In terms of promoting air-rail 

connections, these funds may be used for projects that are on airport 

property or right-of-way owned or controlled by the airport, airport 

owned, and exclusively serves airport traffic. In fiscal year 2013, this 

program was funded at $3.1 billion.a

GAO found no example of its 

use for air-rail projects.

High Speed Intercity 

Passenger Rail grants 

Provides competitively awarded grants to states, interstate compacts, 

and other public agencies, for high-speed and intercity passenger rail 

projects through the Federal Railroad Administration (FRA). Eligible 

projects include acquiring, constructing, improving, or inspecting 

equipment, track, and track structures, or a facility for use in or for the 

primary benefit of high-speed and intercity passenger rail service.

Congress appropriated $8 billion for high-speed rail and intercity 

passenger rail in the American Recovery and Reinvestment Act of 

2009 and $2.5 billion in the fiscal year 2010 Department of 

Transportation (DOT) Appropriations Act.b For fiscal year 2011, $400 

million in unobligated funds were rescinded.

c

Baltimore/Washington 

International Thurgood Marshall 

Airport Amtrak station 

improvements, including 

planning for track and rail 

station upgrades

Passenger Facility

Charge program

Authorizes commercial service airports to charge airline passengers a 

boarding charge of up to $4.50 to be collected by the airlines, after 

obtaining FAA approval. The fees are used by the airports to fund FAA 

approved projects that are on airport property, airport-owned, and 

exclusively serve airport traffic. These projects must enhance the 

safety, security, or capacity of air travel; reduce the impact of aviation 

noise; or increase air carrier competition. In calendar year 2012, $2.8 

billion in fees were collected under this program.

AirTrain automated people 

mover at Newark’s Liberty 

International Airport

Railroad Rehabilitation and 

Improvement Financing 

program 

Provides direct loans and loan guarantees to railroads, state and local 

governments and Amtrak, among other entities, to finance the 

development of railroad infrastructure, including the development of 

new intermodal or railroad facilities. The program, administered by 

FRA, is authorized to provide up to $35 billion in loans or loan 

guarantees for eligible projects.

GAO found no example of its 

use for air-rail projects.

Transportation Investment 

Generating Economic 

Recovery grants 

Provides discretionary grants through DOT, awarded on a competitive 

basis, to fund merit-based transportation projects expected to have a 

significant impact on the nation, a metropolitan area, or a region. Each 

project is multi-modal, multi-jurisdictional, or otherwise challenging to 

fund through existing programs. Eligible projects include capital 

investments in roads, highways, bridges, or transit; passenger and 

freight rail; and port infrastructure; as well as bicycle and pedestrianrelated improvements. In fiscal year 2013, this program was funded at 

$474 million. 

GAO found no example of its 

use for air-rail projects.

Appendix III: Examples of Potential Federal 

Financing and Funding Sources for Air-Rail 

Projects
Appendix III: Examples of Potential Federal 

Financing and Funding Sources for Air-Rail 

Projects

Page 46 GAO-13-691 Intermodal Transportation

Source Description

Example of use for air-rail 

projects

Transportation

Infrastructure

Finance and

Innovation Act of

1998, as amendedd

Provides federal credit assistance for surface transportation projects 

jointly through the Federal Highway Administration, Federal Transit 

Administration, and FRA. Project sponsors may include public, private, 

state, or local entities. Projects eligible for credit assistance include 

intercity passenger rail facilities and vehicles, such as those owned by 

Amtrak, as well as projects otherwise eligible for federal assistance 

through existing surface transportation programs. In fiscal year 2013, 

this program was funded at $750 million.

Miami Intermodal Center at 

Miami International Airporte

Source: GAO analysis.

a

In fiscal year 2013, approximately $3.4 billion was made available for obligation for the AIP program. 

On May 1, 2013, the Reducing Flight Delays Act of 2013 was enacted. It authorized the Secretary of 

Transportation to transfer an amount, not to exceed $253 million, from the AIP program to the FAA 

operations account that the Secretary of Transportation determines to be necessary to prevent 

reduced operations and staffing of the FAA during fiscal year 2013. Pub. L. No. 113-9, 127 Stat. 443.

b Pub. L. No. 111-5, div. A., title XII, 123 Stat. 115, 208 (Feb. 17, 2009); Pub. L. No. 111-117, div. A, 

title I, 123 Stat. 3034, 3056 (Dec. 16, 2009).

c Pub. L. No. 112-10, div. B, title II, § 2222, 125 Stat. 28, 193 (Apr. 15, 2011).

d

23 U.S.C. §§ 601-609.

e

In addition to these funds, the Miami Intermodal Center will also use state and local funding, as well 

as funds generated from rental car facility charges and toll road revenue to complete the project. The 

amount of private funding for this project has yet to be determined.
Appendix IV: Distances between Large and 

Medium Hub Airport Terminals and Amtrak 

Stations in the Contiguous United States

Page 47 GAO-13-691 Intermodal Transportation

Distance between airport and nearest 

Amtrak stationa Airport name Airport location

0 to 5 miles (21 airports) Albuquerque International Sunport Albuquerque, New Mexico

Baltimore/Washington International Thurgood Marshall Glen Burnie, Maryland 

Bob Hope Burbank, California

Bradley International Windsor Locks, Connecticut

Buffalo Niagara International Buffalo, New York

Chicago Midway International Chicago, Illinois

Eppley Airfield Omaha, Nebraska

Fort Lauderdale/Hollywood International Fort Lauderdale, Florida

General Edward Lawrence Logan International Boston, Massachusetts

General Mitchell International Milwaukee, Wisconsin

Metropolitan Oakland International Oakland, California

Miami International Miami, Florida

Newark Liberty International Newark, New Jersey

Norman Y. Mineta San Jose International San Jose, California

Ontario International Ontario, California

Palm Beach International West Palm Beach, Florida

Reno/Tahoe International Reno, Nevada

Ronald Reagan Washington National Arlington, Virginia

Salt Lake City International Salt Lake City, Utah

San Diego International San Diego, California

Seattle-Tacoma International Seattle, Washington

More than 5 miles to 10 miles (21 airports) Austin-Bergstrom International Austin, Texas

Charlotte/Douglas International Charlotte, North Carolina

Chicago O’Hare International Chicago, Illinois

Cincinnati/Northern Kentucky International Greater Cincinnati, Kentucky

Dallas Love Field Dallas, Texas

Detroit Metropolitan Wayne County Detroit, Michigan

Indianapolis International Indianapolis, Indiana

Jacksonville International Jacksonville, Florida

John Wayne Airport-Orange County Santa Ana, California

La Guardia New York, New York

Memphis International Memphis, Tennessee

Minneapolis-St. Paul International/Wold-Chamberlain Minneapolis, Minnesota

Orlando International Orlando, Florida

Philadelphia International Philadelphia, Pennsylvania

Appendix IV: Distances between Large and 

Medium Hub Airport Terminals and Amtrak 

Stations in the Contiguous United States
Appendix IV: Distances between Large and 

Medium Hub Airport Terminals and Amtrak 

Stations in the Contiguous United States

Page 48 GAO-13-691 Intermodal Transportation

Distance between airport and nearest 

Amtrak stationa Airport name Airport location

Portland International Portland, Oregon

Raleigh-Durham International Raleigh, North Carolina

Sacramento International Sacramento, California

San Antonio International San Antonio, Texas

Tampa International Tampa, Florida

Theodore Francis Green State Providence, Rhode Island

William P. Hobby Houston, Texas

More than 10 miles to 20 miles (13 airports) Cleveland-Hopkins International Cleveland, Ohio

Dallas/Fort Worth International Fort Worth, Texas

Denver International Denver, Colorado

George Bush Intercontinental/Houston Houston, Texas

Hartsfield-Jackson Atlanta International Atlanta, Georgia

John F. Kennedy International New York, New York

Kansas City International Kansas City, Missouri

Lambert-St. Louis International St. Louis, Missouri

Los Angeles International Los Angeles, California

Louis Armstrong New Orleans International New Orleans, Louisiana

Pittsburgh International Pittsburgh, Pennsylvania

San Francisco International San Francisco, California

Washington Dulles International Dulles, Virginia

More than 20 miles (5 airports) McCarran International Las Vegas, Nevada

Nashville International Nashville, Tennessee

Phoenix Sky Harbor International Phoenix, Arizona

Port Columbus International Columbus, Ohio

Southwest Florida International Fort Myers, Florida

Source: GAO analysis of National Transportation Atlas Database.

Note: This analysis does not include large and medium hub airports located outside of the contiguous 

United States. Specifically, this analysis does not include Honolulu International Airport in Honolulu, 

Hawaii; Kahului Airport in Kahului, Hawaii; Luis Munoz Marin International Airport in San Juan, Puerto 

Rico; and Ted Stevens Anchorage International Airport in Anchorage, Alaska.

a

The distance between each airport and the nearest Amtrak station was calculated using linear 

distance between the longitude and latitude coordinate of each airport and Amtrak stations, as 

identified in the National Transportation Atlas Database for 2012. The distance between each airport 

and the nearest Amtrak station reflects the linear distance between the two locations, and may be 

affected by existing buildings, roads, bridges, or other obstacles in the path of a traveler connecting 

between an airport and an Amtrak station. Amtrak officials noted that, in some locations, it provides 

service that may operate in close proximity to an airport, but may not have an Amtrak station near 

that airport.
Appendix V: GAO Contact and Staff 

Acknowledgments

Page 49 GAO-13-691 Intermodal Transportation

Gerald L. Dillingham, Ph.D., (202) 512-2834, or dillinghamg@gao.gov

In addition to the contact listed above, Teresa Spisak (Assistant Director), 

Matt Voit, Rosa Leung, Paul Aussendorf, Leia Dickerson, Patrick Dudley, 

Lorraine Ettaro, Jessica Evans, Kathleen Gilhooly, Delwen Jones,

Richard Jorgenson, Jill Lacey, John Mingus, and Josh Ormond made 

major contributions to this product.

Appendix V: GAO Contact and Staff 

Acknowledgments

GAO Contact

Acknowledgments

(540248)
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