INTELLIGENT 

TRANSPORTATION 

SYSTEMS

Vehicle-toInfrastructure 

Technologies 

Expected to Offer 

Benefits, but 

Deployment 

Challenges Exist

Report to Congressional Requesters

September 2015

GAO-15-775

United States Government Accountability Office
Highlights of GAO-15-775, a report to 

congressional requesters

September 2015

INTELLIGENT TRANSPORTATION SYSTEMS

Vehicle-to-Infrastructure Technologies Expected to 

Offer Benefits, but Deployment Challenges Exist

Why GAO Did This Study

Over the past two decades, automobile 

crash-related fatality and injury rates

have declined over 34 and 40 percent 

respectively, due in part to 

improvements in automobile safety. To

further improve traffic safety and 

provide other transportation benefits, 

DOT is promoting the development of

V2I technologies. Among other things,

V2I technologies would allow roadside 

devices and vehicles to communicate 

and alert drivers of potential safety 

issues, such as if they are about to run 

a red light. GAO was asked to review 

V2I deployment. 

This report addresses: (1) the status of 

V2I technologies; (2) challenges that 

could affect the deployment of V2I 

technologies, and DOT efforts to 

address these challenges; and (3) 

what is known about the potential 

benefits and costs of V2I technologies.

GAO reviewed documentation on V2I 

from DOT, automobile manufacturers, 

industry associations, and state and 

local agencies. In addition, GAO 

interviewed DOT, Federal 

Communication Commission (FCC), 

and National Telecommunications 

Information Administration (NTIA) 

officials. GAO also conducted 

structured interviews with 21 experts

from a variety of subject areas related 

to V2I. The experts were chosen based 

on recommendations from the National 

Academy of Sciences and other 

factors. 

DOT, NTIA, and the FCC reviewed a 

draft of this report. DOT and NTIA

provided technical comments, which 

were incorporated as appropriate. FCC 

did not provide comments.

What GAO Found

Vehicle-to-infrastructure (V2I) technologies allow roadside devices to 

communicate with vehicles and warn drivers of safety issues; however, these 

technologies are still developing. According to the Department of Transportation 

(DOT), extensive deployment may occur over the next few decades. DOT, state, 

and local-transportation agencies; researchers; and private-sector stakeholders 

are developing and testing V2I technologies through test beds and pilot 

deployments. Over the next 5 years, DOT plans to provide up to $100 million

through its Connected Vehicle pilot program for projects that will deploy V2I 

technologies in real-world settings. DOT and other stakeholders have also 

provided guidance to help state and local agencies pursue V2I deployments, 

since it will be up to these agencies to voluntarily deploy V2I technologies. 

According to experts and industry stakeholders GAO interviewed, there are a 

variety of challenges that may affect the deployment of V2I technologies 

including: (1) ensuring that possible sharing with other wireless users of the 

radio-frequency spectrum used by V2I communications will not adversely affect 

V2I technologies’ performance; (2) addressing states and local agencies’ lack of 

resources to deploy and maintain V2I technologies; (3) developing technical 

standards to ensure interoperability; (4) developing and managing data security

and addressing public perceptions related to privacy; (5) ensuring that drivers 

respond appropriately to V2I warnings; and (6) addressing the uncertainties 

related to potential liability issues posed by V2I. DOT is collaborating with the 

automotive industry and state transportation officials, among others, to identify 

potential solutions to these challenges.

The full extent of V2I technologies’ benefits and costs is unclear because test 

deployments have been limited thus far; however, DOT has supported initial 

research into the potential benefits and costs. Experts GAO spoke to and 

research GAO reviewed indicate that V2I technologies could provide safety, 

mobility, environmental, and operational benefits, for example by: (1) alerting 

drivers to potential dangers, (2) allowing agencies to monitor and address 

congestion, and (3) providing driving and route advice. V2I costs will include the

initial non-recurring costs to deploy the infrastructure and the recurring costs to 

operate and maintain the infrastructure. While some organizations have 

estimated the potential average costs for V2I deployments, actual costs will 

depend on a variety of factors, including where the technology is installed, and 

how much additional infrastructure is needed to support the V2I equipment. 

Figure 1: Example of a Vehicle-to-Infrastructure Application

View GAO-15-775. For more information, 

contact David Wise at (202) 512-2834 or 

wised@gao.gov. 

United States Government Accountability Office
Letter 1

Background 4

V2I Deployment Efforts Are in the Early Stages and Extensive 

U.S. Deployment May Occur over the Next Few Decades 11

A Variety of Challenges, Including Potential Spectrum Sharing, 

May Affect the Deployment of V2I 18

Extent of Benefits and Costs Are Likely to Remain Unclear until 

Further Deployment of V2I Technology 33

Agency Comments 42

Appendix I Scope and Methodology 44

Appendix II Expert Ratings of Potential Challenges Facing Deployment of 

Vehicle-to-Infrastructure Technologies 51

Appendix III GAO Contact and Staff Acknowledgments 52

Tables

Table 1: Total Potential Average, Non-Recurring Costs of 

Connected Vehicle Infrastructure per Site 40

Table 2: Subject Matter Experts Interviewed 46

Table 3: Expert Ratings of Potential Challenges Facing 

Deployment of Vehicle-to-Infrastructure Technologies 51

Figures

Figure 1: Examples of Vehicle-to-Infrastructure Applications 6

Figure 2: Example of Vehicle-to-Infrastructure Application 

Provided through Roadside Equipment 10

Figure 3: DOT’s Planned Connected Vehicle Path to Deployment, 

2010-2040 17

Contents

Page i GAO-15-775 Intelligent Transportation Systems
Abbreviations

AASHTO American Association of State Highway and Transportation 

Officials 

ANPRM Advanced Notice of Proposed Rulemaking 

CAMP Crash Avoidance Metrics Partners, LLC

CO-Pilot Cost Overview for Planning Ideas and Logical 

Organization Tool 

DOT U.S. Department of Transportation

DSRC dedicated short-range communications

GHz gigahertz

FCC Federal Communications Commission 

FHWA Federal Highway Administration 

IEEE Institute of Electrical and Electronics Engineers 

ITS intelligent transportation system 

ITS America Intelligent Transportation Society of America 

ITS-JPO Intelligent Transportation Systems-Joint Program Office

MHz megahertz

MLIT Ministry of Land, Infrastructure, Transport and Tourism 

(Japan)

NCHRP National Cooperative Highway Research Program

NHTSA National Highway Traffic Safety Administration 

NTIA National Telecommunications and Information 

Administration

RSE roadside equipment 

RSU roadside unit

SAE Society for Automotive Engineers International 

SCMS Security Credential Management System 

SPaT Signal Phase and Timing 

TMC traffic management center 

V2I vehicle-to-infrastructure 

V2V vehicle-to-vehicle 

VICS Vehicle Information and Communication System (Japan)

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 

copyrighted images or other material, permission from the copyright holder may be 

necessary if you wish to reproduce this material separately.

Page ii GAO-15-775 Intelligent Transportation Systems
441 G St. N.W.

Washington, DC 20548

September 15, 2015

The Honorable Barbara Comstock

Chairwoman

The Honorable Daniel Lipinski

Ranking Member

Subcommittee on Research and Technology

Committee on Science, Space, and Technology

House of Representatives

The Honorable Larry Bucshon

House of Representatives

Over the past two decades, automobile crash-related fatality and injury 

rates have declined nearly 34 percent and 40 percent, respectively, due 

in part to automobile safety features like safety belts and airbags.1 The 

U.S. Department of Transportation (DOT) is working to further improve 

traffic safety through its connected vehicle research program, which aims 

to develop innovative technologies that enable vehicles, road 

infrastructure, and personal communications devices to wirelessly 

communicate and warn drivers and pedestrians of potential accidents. 

For example, DOT is collaborating with the automobile industry, academic 

institutions, technology firms, and state and local agencies to develop 

vehicle-to-infrastructure (V2I) technologies that allow vehicles to 

“communicate” with road infrastructure (such as traffic signals) through 

the wireless exchange of data. These technologies can enable the 

development of V2I software applications2 that could, among other things: 

warn drivers of upcoming road conditions, such as work zones, or that 

they are approaching a curve at an unsafe speed; adjust traffic signal 

lights to provide priority to emergency vehicles or to address congestion; 

advise drivers about upcoming traffic and alternative routes; and provide 

driving advice to minimize stop-and-go driving.3 For example, in 2011, 

1

Department of Transportation (DOT) National Highway Traffic Safety Administration 

(NHTSA), Traffic Safety Facts 2013, DOT HS 812 139 (Washington, DC).

2

A variety of software applications are being developed that would use V2I technologies to 

provide different types of information to drivers.

3

These are just a few examples of V2I applications: DOT has defined over 40 potential 

applications that would serve a wide range of functions. 

Letter

Page 1 GAO-15-775 Intelligent Transportation Systems

 
Japan implemented V2I through the deployment of the ITS Spot system. 

ITS Spot uses roadside equipment to collect and share data with vehicles 

in order to provide three basic services to drivers: dynamic route 

guidance, safe driving support, and electronic toll collection. Japan’s 

extensive V2I network includes roughly 55,000 pieces of V2I equipment 

on local roads and 1,600 pieces of V2I equipment on its approximately 

11,000 kilometers of expressways. Similarly, the Netherlands, Germany, 

and Austria are working to develop a European smart corridor that will 

provide drivers information on road work and upcoming traffic, among 

other things. Since V2I technologies are still in development in the United 

States and rely on the exchange of information between vehicles and 

infrastructure, developing and deploying V2I will require the collaboration 

of a number of stakeholders, particularly state and local agencies, as well 

as auto manufacturers.

In light of research showing the potential for V2I technologies to reduce 

traffic accidents and fatalities, as well as questions raised regarding 

potential technological and policy challenges, you asked us to review 

issues related to V2I technologies. We examined: (1) the status of V2I 

technologies; (2) the challenges, if any, that could affect the deployment 

of V2I technologies, and DOT efforts to address these challenges; and (3) 

what is known about the potential benefits and costs of V2I technologies. 

To address these issues, we reviewed documentation relevant to the V2I 

technology research efforts of DOT, state and local governments, and the 

automobile industry, including DOT’s 2015 Federal Highway 

Administration (FHWA) V2I Draft Deployment Guidance and Products4

and the American Association of State Highway and Transportation 

Officials’ (AASHTO) National Connected Vehicle Field Infrastructure 

Footprint Analysis. We interviewed officials from DOT’s Office of the 

Assistant Secretary for Research and Technology, Intelligent 

Transportation Systems-Joint Program Office (ITS-JPO), FHWA, National 

Highway Traffic Safety Administration (NHTSA), and the Volpe National 

Transportation Systems Center about these efforts. In addition to DOT 

and its agencies, we also interviewed an additional 12 stakeholders that 

were involved in V2I efforts, such as associations representing state 

transportation agencies and engineers.5 We interviewed officials at all 

4

DOT, 2015 FHWA Vehicle to Infrastructure Deployment Guidance and Products (Draft), 

version 9 (September 9, 2014).

5

We primarily selected stakeholders based on recommendations from DOT and industry 

associations.

Page 2 GAO-15-775 Intelligent Transportation Systems

 
seven V2I test beds located in Virginia, Michigan, Florida, Arizona, 

California, and New York.6 We conducted site visits to three of the seven 

test beds—the Safety Pilot in Ann Arbor, Michigan, and the test beds in 

Southeast Michigan and Northern Virginia. We selected the three site visit 

locations based on which had the most advanced technology according to 

DOT and state officials. We used our interviews with stakeholders to help 

us understand the issues, and developed a structured set of questions for 

interviews with 21 experts, nine of whom were identified by the National 

Academy of Sciences. We selected an additional 12 experts based on the 

following factors: (1) their personal involvement in the deployment of V2I 

technologies; (2) recommendations from federal agencies and industry 

associations; and, (3) experts’ involvement in a professional affiliation 

such as a V2I consortium or group dedicated to these technologies, or 

expertise on a specific challenge affecting V2I (e.g., privacy). The 21 

experts we selected included domestic automobile manufacturers, V2I 

equipment suppliers, state and local government officials, privacy experts, 

global industry organizations responsible for developing technology 

standards, and academic researchers with relevant expertise. During 

these interviews we asked, among other things, for experts’ views on the 

state of development and deployment of V2I technologies (including 

DOT’s role in this process), the potential benefits of V2I technologies, and 

their potential costs.7 In our report, we use the term “experts” to refer to 

the 21 selected individuals we interviewed using a structured set of 

questions; we use the term “stakeholders” to refer to those individuals we 

spoke with, but that were not interviewed using the structured set of 

questions. The viewpoints gathered through our expert interviews 

represent the viewpoints of these specific individuals and cannot be 

generalized to a broader population.

We also interviewed officials from the Federal Communications 

Commission (FCC) and National Telecommunications and Information 

Administration (NTIA) within the Department of Commerce regarding 

challenges related to the potential for spectrum sharing with V2I 

technologies. Finally, we conducted a site visit to Japan because of its 

years of experience with deployment and maintenance of its national V2I 

6

There are two test beds in Michigan, the Safety Pilot in Ann Arbor, Michigan, and one in 

Southeast Michigan, in Oakland County. 

7

In conducting our structured interviews, we used a standardized interview guide to 

ensure that we asked all of the experts the same questions.

Page 3 GAO-15-775 Intelligent Transportation Systems

 
system.8 During our site visit, we interviewed Japanese government 

officials responsible for V2I and auto manufacturers on topics similar to 

those discussed with U.S. experts, including V2I deployment efforts, 

benefits, costs, and challenges. Information about Japan’s V2I efforts 

provides an illustrative example from which to draw information on the

potential benefits, costs, and challenges of deploying V2I technologies in 

the United States. Further details about our scope and methodology can 

be found in appendix I.

We conducted this performance audit from July 2014 to September 2015 

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.

DOT is working with the automobile industry, state and local 

transportation agencies, researchers, private sector stakeholders, and 

others to lead and fund research on connected vehicle technologies to 

enable safe wireless communications among vehicles, infrastructure, and 

travelers’ personal communications devices.9 Connected vehicle 

technologies include vehicle-to-vehicle (V2V) and vehicle-to-infrastructure 

(V2I) technologies:

• V2V technologies transmit data between vehicles to enable 

applications that can warn drivers about potential collisions. 

8

In the 1990s, Japan introduced its Vehicle Information and Communication System 

(VICS), which provides real-time road traffic information to drivers via a VICS-equipped 

navigation device. In 2011, Japan implemented V2I with its deployment of ITS Spot. In 

2010, DOT and Japan’s Ministry of Land, Infrastructure, Transport, and Tourism (MLIT) 

signed a memorandum of cooperation to promote bilateral collaboration in the field of ITS.

9

This effort is part of DOT’s Intelligent Transportation Systems Program (ITS). ITS 

technologies consist of a range of communications, electronics, and computer 

technologies, such as systems that collect real-time traffic data and transmit information to 

the public via means such as dynamic message signs, ramp meters to improve the flow of 

traffic on freeways, and synchronized traffic signals that are adjusted in response to traffic 

conditions. From fiscal years 2003 through 2014, DOT provided about $570 million in 

funding for connected vehicle technologies. Funding for these efforts ranged from a low of 

$17 million in 2008 to a high of $84 million in 2011. These figures are not adjusted for 

inflation.

Background

Page 4 GAO-15-775 Intelligent Transportation Systems

 
Specifically, V2V-equipped cars would emit data on their speed, 

position, heading, acceleration, size, brake status, and other data 

(referred to as the “basic safety message”) 10 times per second to the

on-board equipment of surrounding vehicles, which would interpret 

the data and provide warnings to the driver as needed. For example, 

drivers may receive a forward collision warning when their vehicle is 

close to colliding with the vehicle in front of them. V2V technologies 

have a greater range of detection than existing sensor-based crash 

avoidance technologies available in some new vehicles.10 NHTSA is 

pursuing actions to require that vehicle manufacturers install the 

underlying V2V technologies that would enable V2V applications in 

new passenger cars and light truck vehicles, and requested comment 

on this issue in an August 2014 Advanced Notice of Proposed 

Rulemaking.11 We reported on V2V technologies in November 2013.12

Thus, we are not focusing on these technologies in this report.

• Vehicle-to-infrastructure (V2I) technologies transmit data between 

vehicles and the road infrastructure to enable a variety of safety, 

mobility, and environmental applications. V2I applications are 

designed to avoid or mitigate vehicle crashes, particularly those crash 

scenarios not addressed by V2V alone, as well as provide mobility 

and environmental benefits. Unlike V2V, DOT is not considering 

mandating the deployment of V2I technologies.

V2I applications rely on data sent between vehicles and infrastructure to 

provide alerts and advice to drivers. For example, the Spot Weather 

Impact Warning application is designed to detect unsafe weather 

conditions, such as ice or fog, and notify the driver if reduced speed or an 

alternative route is recommended (see left side of figure 1). DOT is also 

investigating the development of V2I mobility and environmental 

applications. For example, the Eco-Approach and Departure at Signalized 

Intersections application alerts drivers of the most eco-friendly speed for 

approaching and departing signalized intersections to minimize stop-and10For example, due to the sharing of data between vehicles, V2V technologies are 

capable of alerting drivers to potential collisions that are not visible to existing sensorbased technologies, such as a stopped vehicle blocked from view or a moving vehicle at a 

blind intersection. See GAO, Intelligent Transportation Systems: Vehicle-to-Vehicle 

Technologies Expected to Offer Safety Benefits, but a Variety of Deployment Challenges 

Exist, GAO-14-13 (Washington, D.C.: Nov. 1, 2013).

1179 Fed. Reg. 49270 (Aug. 20, 2014).

12GAO-14-13.

Page 5 GAO-15-775 Intelligent Transportation Systems

 
go traffic and idling (see right side of fig. 1), and eco-lanes, combined with 

eco-speed harmonization, (demonstrated in the following video) would 

provide speed limit advice to minimize congestion and maintain 

consistent speeds among vehicles in dedicated lanes.

Figure 1: Examples of Vehicle-to-Infrastructure Applications

DOT is also pursuing the development of V2I mobility applications that 

are designed to provide traffic signal priority to certain types of vehicles, 

such as emergency responders or transit vehicles. In addition, other types 

of V2I mobility applications could capture data from vehicles and 

infrastructure (for example, data on current traffic volumes and speed) 

and relay real-time traffic data to transportation system managers and 

drivers. For example, after receiving data indicating vehicles on a 

particular roadway were not moving, transportation system managers 

could adjust traffic signals in response to the conditions, or alert drivers of 

alternative routes via dynamic message signs located along the roadway. 

In addition to receiving alerts via message signs, these applications could 

also allow drivers to receive warnings through on-board systems or 

personal devices. Japan has pursued this approach through its ITS Spot 

Page 6 GAO-15-775 Intelligent Transportation Systems
V2I initiative, which uses roadside devices located along expressways to 

simultaneously collect data from vehicles to allow traffic managers to 

identify congestion, while also providing information to drivers regarding 

upcoming congestion and alternative routes.13

To communicate in a connected vehicle environment, vehicles and 

infrastructure must be equipped with dedicated short-range 

communications (DSRC), 14 a wireless technology that enables vehicles 

and infrastructure to transmit and receive messages over a range of 

about 300 meters (nearly 1,000 feet).15 As previously noted, V2Vequipped cars emit data on their speed, position, heading, acceleration, 

size, brake status, and other data (referred to as the “basic safety 

message”) 10 times per second to the surrounding vehicles and 

infrastructure. V2I-equipped infrastructure can also transmit data to 

vehicles, which can be used by on-board applications to issue appropriate 

warnings to the driver when needed. According to DOT, DSRC is 

considered critical for safety applications due to its low latency,16 high 

reliability, and consistent availability. In addition, DSRC also transmits in a 

broadcast mode, providing data to all potential users at the same time. 

Stakeholders and federal agencies have noted that DSRC’s ability to 

reliably transfer messages between infrastructure and rapidly moving 

vehicles is an essential component to detecting and preventing potential 

collisions. DSRC technology uses radiofrequency spectrum to wirelessly 

send and receive data.17 The Federal Communications Commission 

13Along expressways linking cities in Japan, ITS Spots are installed approximately every 

10-15 kilometers and on inner-city expressways, ITS Spots are installed every 4 

kilometers. An in-vehicle V2I application collects, stores, and uploads (via ITS Spot road 

infrastructure) an anonymous travel and behavior record of the vehicle, which contains 

information about the time, position, speed, acceleration, and angle of the vehicle.

14According to DOT, DSRC technology is the designated communications technology for 

communications-based active safety-systems research. 

15DSRC is used for safety-critical applications that cannot tolerate interruption; however, 

DOT has noted that other technologies (such as cellular or satellite, among others) may 

be used for non-safety-critical applications. 

16Latency refers to the relative response time in communications between the originating 

and the responding application components (onboard unit and/or roadside unit and/or 

back office services) needed for the application to be effective. 

17Radio-frequency spectrum is a natural resource that is used to provide an array of 

wireless communications services critical to the U.S. economy and a variety of 

government functions. 

Page 7 GAO-15-775 Intelligent Transportation Systems

 
(FCC), which manages spectrum for nonfederal users, including 

commercial, private, and state and local government users, allocated 75 

megahertz (MHz) of spectrum—the 5.850 to 5.925 gigahertz (GHz) band 

(5.9 GHz band)18—for the primary purpose of improving transportation 

safety and adopted basic technical rules for DSRC operations.19

However, in response to increased demands for spectrum,20 FCC has 

requested comment on allowing other devices to “share” the 5.9 GHz 

band with DSRC technologies.21

V2I equipment may vary depending on the location and the type of 

application being used, although in general, V2I components in the 

connected vehicle environment include an array of roadside equipment 

(RSE) that transmits and receives messages with vehicles for the 

purpose of supporting V2I applications (see figure 2). For example, a V2Iequipped intersection would include:

18In the United States, responsibility for spectrum management is divided between two 

agencies: FCC and the Department of Commerce’s National Telecommunications and 

Information Administration (NTIA). FCC manages spectrum use for nonfederal users, 

including commercial, private, and state and local government users and NTIA manages 

spectrum for federal government users and acts for the President with respect to spectrum 

management issues. Historically, concern about interference or crowding among users 

has been a driving force in the management of spectrum. In order to minimize 

interference, FCC and NTIA have allocated particular bands of spectrum for specific uses, 

and provided users with a license or authorization to use a specific portion of spectrum. 

According to NTIA, the FCC will issue the licenses for the non-federal DSRC systems. 

DOT’s spectrum use is authorized by NTIA. 75 Fed. Reg. 38387 (July 1, 2010).

19Amendment of Parts 2 and 90 of the Commission’s Rules to Allocate the 5.850-5925 

GHz Band to the Mobile Service for Dedicated Short Range Communications of Intelligent 

Transportation Services, Report and Order, 14 FCC Rcd 18221 (1999)(FCC 99-305). 

20As new spectrum-dependent technologies and services are brought to market and 

government users develop new mission needs, the demand for spectrum continues to 

increase and additional capacity will be needed to accommodate future growth that cannot 

be addressed through more efficient use of wireless technologies. One driver of the 

increased demand for spectrum has been the significant growth in commercial wireless 

broadband services, smart phones, and tablet computers. See GAO, Spectrum 

Management: FCC’s Licensing Approach in the 11, 18, and 23 Gigahertz Bands Currently 

Supports Spectrum Availability and Efficiency, GAO-13-78R (Washington, D.C.: 

November 20, 2012).

21In the Matter of Revision of Part 15 of the Commission’s Rules to Permit Unlicensed 

National Information Infrastructure (U-NII) Devices in the 5 GHz Band, 28 FCC Rcd 1769,

(2014). The operator on an unlicensed device must accept whatever interference is 

received from the DSRC devices and must correct whatever interference is caused to 

DSRC devices. 47 C.F.R. § 15.5.

Page 8 GAO-15-775 Intelligent Transportation Systems

 
• Roadside units (RSU)—a device that operates from a fixed position 

and transmits data to vehicles. This typically refers to a DSRC radio,22

which is used for safety-critical applications that cannot tolerate 

interruption, although DOT has noted that other technologies may be 

used for non-safety-critical applications.

• A traffic signal controller that generates the Signal Phase and Timing 

(SPaT) message, which includes the signal phase (green, yellow, and 

red) and the minimum and maximum allowable time remaining for the 

phase for each approach lane to an intersection. The controller 

transfers that information to the RSU, which broadcasts the message 

to vehicles.

• A local or state back office, private operator, or traffic management 

center that collects and processes aggregated data from the roads 

and vehicles. As previously noted, these traffic management centers 

may use aggregated data that is collected from vehicles (speed, 

location, and trajectory) and stripped of identifying information to gain 

insights into congestion and road conditions as well.23

• Communications links (such as fiber optic cables or wireless 

technologies) between roadside equipment and the local or state back 

office, private operator, or traffic management center. This is typically 

referred to as the “backhaul network.”

• Support functions, such as underlying technologies and processes to 

ensure that the data being transmitted are secure.

22When referring to the DSRC radio alone, the term roadside unit (RSU) is used. 

23Currently, state and local traffic-management centers gather and process traffic data, 

such as information on accidents and congestion, and take steps to respond to conditions,

such as notifying emergency personnel, adjusting traffic signals, and providing alerts to 

drivers via roadway signs.

Page 9 GAO-15-775 Intelligent Transportation Systems

 
Figure 2: Example of Vehicle-to-Infrastructure Application Provided through Roadside Equipment

Page 10 GAO-15-775 Intelligent Transportation Systems
DOT, state and local transportation agencies, academic researchers, and 

private sector stakeholders are engaged in a number of efforts to develop 

and test V2I technologies and applications, as well as to develop the 

technology and systems that enable V2I applications. DOT’s V2I work is 

funded through its connected vehicle research program. DOT’s initial 

connected vehicle research focused on V2I technologies; however, it 

shifted its focus to V2V technologies because they are projected to 

produce the majority of connected vehicle safety benefits and they do not 

require the same level of infrastructure investment as V2I technologies. 

After conducting much of the research needed to inform its advanced 

notice of proposed rulemaking to require that vehicle manufacturers 

install V2V technologies in new passenger cars and light truck vehicles, 

DOT is now shifting its focus back to V2I technologies, and some of the 

technical work needed to develop V2V applications has also informed the 

development of V2I.24 A number of DOT agencies are involved with the 

development and deployment of V2I technologies.25 In addition, private 

companies have received contracts from DOT to develop the underlying 

concept of operations and technologies to support V2I applications, and 

auto manufacturers are collaborating with DOT in its efforts to develop 

2479 Fed. Reg. 49270 (Aug. 20, 2014).

25DOT’s ITS-JPO is responsible for research execution and initial technology transfer 

activities, such as field testing. FHWA is coordinating with the states and developing the 

materials to support V2I deployment, such as guides, tools, and best practices—and is 

working to ensure that deployed services are geographically interoperable and that 

deployed services are developed in accordance with federal regulations. The Volpe 

National Transportation Systems Center provides technical support to ITS-JPO and 

FHWA, and conducts some laboratory testing for V2I technologies, as well as estimating 

safety benefits of connected vehicle technologies.

V2I Deployment 

Efforts Are in the 

Early Stages and 

Extensive U.S. 

Deployment May 

Occur over the Next 

Few Decades

DOT and Various 

Stakeholders Are 

Developing and Testing 

V2I Technologies through 

Small Test Deployments

Page 11 GAO-15-775 Intelligent Transportation Systems

 
and pilot certain V2I applications and the underlying technologies to 

support them. State and local transportation agencies, which will 

ultimately be deploying V2I technologies on their roads, have also 

pursued efforts to test V2I technologies in real-world settings. However, to 

date, only small research deployments (such as those described below) 

have occurred to test V2I technologies:

• The Safety Pilot Model Deployment: DOT partnered with the 

University of Michigan Transportation Research Institute to collect 

data to help estimate the effectiveness of connected vehicle 

technologies and their benefits in real-world situations. The pilot was 

conducted in Ann Arbor, Michigan, from August 2012 to February 

2014, and included roughly 2,800 V2V-equipped cars, trucks, and 

buses, as well as roadside V2I equipment placed at 21 intersections, 

three curve-warning areas, and five freeway sites. While the primary 

focus was on V2V technologies, the pilot also evaluated V2I 

technology, such as Signal Phase and Timing (SPaT) technologies. 

DOT officials stated that it would be releasing six reports with findings 

from the Safety Pilot in mid to late 2015, although these reports will 

primarily focus on V2V applications. As of July 2015, DOT has 

released one report that included an evaluation of how transit bus 

drivers responded to V2V and V2I warnings, and of how well the test 

applications performed in providing accurate warnings.26 The two V2I

applications included were a curve speed warning and a warning that 

alerts the bus driver if pedestrians are in the intended path of the bus 

when it is turning at an intersection.

• Connected Vehicle Pooled Fund Study: A group of state 

transportation agencies, with support from the FHWA, established the 

Connected Vehicle Pooled Fund Study.27 The study aims to aid 

26The report concluded that the transit safety applications have the potential to improve 

driver behavior and increase driver safety, but that improvements were needed to 

increase the accuracy of the warnings provided by the transit safety applications. For 

example, the report noted that the curve speed warning was provided early enough for the 

driver to take action only 57 percent of the time. U.S. Department of Transportation’s 

Federal Highway Administration, Independent Evaluation of the Transit Retrofit Package 

Safety Applications, FHWA-JPO-14-175 (Washington, D.C.: February 2015). 

27The primary members of the Connected Vehicle Pooled Fund Study include FHWA and 

transportation representatives from Virginia, California, Florida, Michigan, Minnesota, 

Maricopa County (Arizona), New Jersey, New York, Pennsylvania, Texas, Utah, 

Washington, and Wisconsin. Virginia serves as the lead state, with support from the 

University of Virginia. 

Page 12 GAO-15-775 Intelligent Transportation Systems

 
transportation agencies in justifying and promoting the large scale 

deployment of a connected vehicle environment and applications 

through modeling, development, engineering, and planning activities. 

To achieve this goal, the study funds projects that facilitate the field 

demonstration, deployment, and evaluation of connected vehicle 

infrastructure and applications. For example, the University of Arizona 

and the University of California at Berkeley are collaborating on a 

project to develop and test an intelligent traffic-signal system that 

could, among other things, provide traffic signal priority for emergency 

and transit vehicles, and allow pedestrians to request for more time to 

cross the street.

• Crash Avoidance Metrics Partners, LLC (CAMP): CAMP—a 

partnership of auto manufacturers that works to accelerate the 

development and implementation of crash avoidance 

countermeasures—established a V2I Consortium that focuses on 

addressing the technical issues related to V2I. In 2013, DOT awarded 

a cooperative agreement to CAMP, with a total potential federal share 

of $45 million, to develop and test V2I safety, mobility, and 

environmental applications, as well as the underlying technology 

needed to support the applications, such as security and GPSpositioning technologies. According to an FHWA official, CAMP’s 

current efforts include developing, testing, and validating up to five V2I 

safety applications, as well as a prototype for Cooperative Adaptive 

Cruise Control, an application that uses V2V and V2I technology to 

automatically maintain the speed of and space between vehicles. In 

addition to CAMP, automakers have established the Vehicle 

Infrastructure Integration Consortium, which coordinates with DOT on 

connected vehicle policy issues, such as interoperability of V2I 

technologies.

• Test Beds: DOT, state and local agencies, and universities have 

established connected vehicle test beds. Test beds provide 

environments (with equipped vehicles and V2I roadside equipment) 

that allow stakeholders to create, test, and refine connected vehicle 

technologies and applications. This includes DOT’s Southeast 

Michigan Test Bed, which has been in operation since 2007 to provide 

a real-world setting for developers to test V2I and V2V concepts, 

applications, technology, and security systems. In addition, state 

agencies and universities have established their own test beds. For 

example, the University Transportation Center in Virginia, in 

collaboration with the Virginia Department of Transportation, 

established the Northern Virginia Test Bed to develop and test V2I 

applications, some of which target specific problems—like 

congestion—along the I-66 corridor. DOT offers guidance on how 

Page 13 GAO-15-775 Intelligent Transportation Systems
research efforts can become DOT-affiliated test beds, with the goal of 

enabling test beds to share design information and lessons learned, 

as well as to create a common technical platform. According to DOT, 

there are over 70 affiliated test bed members. The deployment of 

connected vehicle infrastructure to date has been conducted in test 

beds in locations such as Arizona, California, Florida, Michigan, New 

York, and Virginia.28 Additionally, officials from some of these test 

beds told us they may apply to the Connected Vehicle Pilot 

Deployment Program later this year (see below).

• The Connected Vehicle Pilot Deployment Program: Over the next 

5 years, DOT plans to provide up to $100 million in funding for a 

number of pilot projects that are to design and deploy connected 

vehicle environments (comprised of various V2I and V2V technologies 

and applications) to address specific local needs related to safety, 

mobility, and the environment. As envisioned, there are to be multiple 

pilot sites with each site having different needs, purposes, and 

applications.29 The program solicitation notes that successful 

elements of the pilot deployments are expected to become permanent 

operational fixtures in the real-world setting (rather than limited to 

particular testing facilities), with the goal of creating a foundation for 

expanded and enhanced connected vehicle deployments. FHWA 

solicited applications for the pilot program from January through 

March 2015. According to DOT, the initial set of pilot deployments 

(Wave 1 award) is expected to begin in Fall 2015, with a second set 

(Wave 2 award) scheduled to begin in 2017. Pilot deployments are 

expected to conclude in September 2020.

28In addition, the University of Michigan’s Mobility Transformation Center is launching a 

test facility to research automated vehicle technologies, including V2I. 

29DOT has provided examples of the types of V2I applications that can be included in the 

pilot projects, and has noted that the applications used will be influenced by what local 

need the project is trying to address. For example, a pilot project may be located in a rural 

area with extreme weather and may include applications that improve access to weatherrelated warnings and that improve safety at highway crossings. Another project may be 

located in an urban area with poor air quality and thus include applications that address 

congestion, pedestrian safety, and vehicular emissions in the downtown area.

Page 14 GAO-15-775 Intelligent Transportation Systems

 
DOT and other stakeholders have worked to provide guidance to help 

state and local agencies pursue V2I deployments, since it will be up to 

state and local transportation agencies to voluntarily deploy V2I 

technologies.30 In September 2014, FHWA issued and requested 

comment on draft V2I deployment guidance intended to help 

transportation agencies make appropriate V2I investment and 

implementation decisions. For example, the guidance includes 

information on planning deployments, federal funding that can be used for 

V2I equipment and operations, technical requirements for equipment and 

systems, and applicable regulations, among other things. FHWA is 

updating the guidance and creating complementary guides, best 

practices, and toolkits, and officials told us they expect the revised 

guidance to be released by September 2015.31 In addition, the American 

Association of State Highway and Transportation Officials (AASHTO),32 in 

collaboration with a number of other groups, developed the National 

Connected Vehicle Field Infrastructure Footprint Analysis.

33 This report 

provides a variety of information and guidance for state and local 

agencies interested in V2I implementation, including a description of 

benefits; various state/local based scenarios for V2I deployments; 

underlying infrastructure and communications needs; timelines and 

activities for deployment; estimated costs and workforce requirements; 

and an identification of challenges that need to be addressed. AASHTO, 

with support the Institute of Transportation Engineers34 and the Intelligent 

30As previously noted, unlike V2V, DOT is not considering mandating the deployment of 

V2I.

31For example, some of the tools FHWA is developing include a V2I Benefit Cost Analysis 

Tool; V2I Planning Guide; Guide to V2I Cyber-Security; Guide to Licensing DSRC 

Roadside Units; Guide to V2I Communication Technology Selection; V2I Message 

Lexicon (a list of allowable standard messages and formats for transmitted information for 

in-vehicle use); Guide to Initial Deployments; and Warrants for Deployment (a set of 

criteria which can be used to define the relative need for and appropriateness of a 

particular V2I application).

32AASHTO is a nonprofit association that serves as a liaison between state departments 

of transportation and the federal government. 

33American Association of State Highway and Transportation Officials, National 

Connected Vehicle Field Infrastructure Footprint Analysis FHWA-JPO-14-125

(Washington, D.C.: June 2014).

34The Institute of Transportation Engineers is an international educational and scientific 

association of transportation professionals who are responsible for meeting mobility and 

safety needs.

DOT and Stakeholders 

Are Collaborating and 

Developing V2I Guidance 

for State and Local 

Agencies

Page 15 GAO-15-775 Intelligent Transportation Systems

 
Transportation Society of America,35 is also leading a V2I Deployment 

Coalition. The Coalition has several proposed objectives: support 

implementation of FHWA V2I deployment guidance; establish connected 

vehicle deployment strategies, and support standards development. 

According to information from the coalition and DOT, the V2I Deployment 

Coalition will be supported by technical teams drawn from DOT, trade 

associations, transportation system owners/operators, and auto 

manufacturers.

While early pilot-project deployment of V2I technologies is occurring, V2I 

technologies are not likely to be extensively deployed in the United States 

for the next few decades. According to DOT, V2I technologies will likely 

be slowly deployed in the United States over a 20-year period as existing 

infrastructure systems are replaced or upgraded. DOT has developed a 

connected vehicle path to deployment that includes steps such as 

releasing the final version of FHWA’s V2I deployment guidance for state 

and local transportation agencies (September 2015),36 and awarding and 

evaluating the Connected Vehicle Pilot Deployment Program projects in 

two phases, with the first phase of awards occurring in September 2015 

and evaluation occurring in 2019, and the second phase of awards 

occurring in September 2017 and evaluation occurring in 2021. In 

addition, DOT officials noted that V2I will capitalize on V2V, and its 

deployment will lag behind the V2V rulemaking. NHTSA will issue a final 

rule specifying whether and when manufacturers will be required to install 

V2V technologies in new passenger cars and light trucks.37 In addition, 

FCC has not made a decision about whether spectrum used by DSRC 

can be shared with unlicensed devices, which could affect the time 

frames for V2I deployment. Even after V2I technologies and applications 

have been developed and evaluated through activities such as the pilot 

35The Intelligent Transportation Society of America (ITS America) is a national 

organization dedicated to advancing the research, development, and deployment of 

Intelligent Transportation Systems (ITS) to improve the nation’s surface transportation 

system. Founded in 1991, ITS America’s membership includes more than 450 public 

agencies, private sector companies, and academic and research institutions.

36DOT officials noted that this will be the final version of initial guidance, and that FHWA 

intends to update this guidance over time.

37Equipping cars with V2V technologies should allow them to receive V2I messages from 

roadside infrastructure; however, it is possible that stand-alone, after-market safety 

devices could be purchased to equip existing vehicles.

Extensive Deployment

of V2I Technologies May

Occur over the Next

Few Decades

Page 16 GAO-15-775 Intelligent Transportation Systems

 
program, it will take time for state and local transportation agencies to 

deploy the infrastructure needed to provide V2I messages, and for drivers 

to purchase vehicles or equipment that can receive V2I messages. 

AASHTO estimated that 20 percent of signalized intersections will be V2Icapable by 2025, and 80 percent of signalized intersections would be V2Icapable by 2040. Similarly, AASHTO estimated that 90 percent of light 

vehicles would be V2V-equipped by 2040. However, DOT officials noted 

that environmental and mobility benefits can occur even without 

widespread market penetration and that other research has indicated 

certain intersections may be targeted for deployment. Similarly, in its 

National Connected Vehicle Field Infrastructure Footprint Analysis, 

AASHTO noted that early deployment of V2I technologies will likely occur 

at the highest-volume signalized intersections, which could potentially 

address 50 percent of intersection crashes.38 See figure 3 for a list of 

planned events and milestones related to DOT’s path to deployment of 

connected vehicle technologies.

Figure 3: DOT’s Planned Connected Vehicle Path to Deployment, 2010-2040

38AASHTO cited research from the March 2009 Noblis report, Footprint Analysis for 

IntelliDriveSM V2V Applications, Intersection Safety Applications, and Tolled Facilities,

which found that twenty percent of intersections in the three largest metro areas 

accounted for 50 percent of the collisions. However, the study does not directly address 

but only infers the safety benefits of V2I-enabling signalized intersections. 

Page 17 GAO-15-775 Intelligent Transportation Systems

 
According to experts and industry stakeholders we interviewed, there are 

a variety of challenges that may affect the deployment of V2I technologies 

including: (1) ensuring that possible sharing with other wireless users of 

the radiofrequency spectrum used by V2I communications will not 

adversely affect V2I technologies’ performance; (2) addressing states’

lack of resources to deploy and maintain V2I technologies; (3) developing 

technical standards to ensure interoperability between devices and 

infrastructure; (4) developing and managing a data security system and 

addressing public perceptions related to privacy; (5) ensuring that drivers 

respond appropriately to V2I warnings; and (6) addressing the 

uncertainties related to potential liability issues posed by V2I. DOT is 

collaborating with the automotive industry and state transportation 

officials, among others, to identify potential solutions to these challenges.

As previously noted, V2I technologies depend on radiofrequency 

spectrum, which is a limited resource in high demand due in part to the 

increase in mobile broadband use. To address this issue, the current and 

past administrations, Congress, FCC, and others have proposed a variety 

of policy, economic, and technological solutions to support the growing 

needs of businesses and consumers for fixed and mobile broadband 

communications by providing access to additional spectrum.39 One 

proposed solution, introduced in response to requirements in the Middle 

Class Tax Relief and Job Creation Act of 2012,40 would allow unlicensed 

devices41 to share the 5.9 GHz band radiofrequency spectrum that had 

been previously set aside for the use of DSRC-based ITS applications 

39In a previous GAO report, we found that that the scarcity of spectrum in the United 

States is to some extent a result of the manner in which this resource has been allocated, 

managed, and used, rather than because of a physical scarcity of the resource. GAO, 

Spectrum Management: Incentives, Opportunities, and Testing Needed to Enhance 

Spectrum, GAO-13-7 (Washington, D.C.: November 2012). 

40Pub. L. No. 112-96, §6406, 126 Stat. 156, 231.

41Traditional unlicensed equipment consists of low powered devices that operate in a 

limited geographic range, such as garage door openers and devices that offer wireless 

access to the Internet. They include Wi-Fi-enabled local area networks and fixed outdoor 

broadband transceivers used by wireless Internet service providers to connect devices to 

broadband networks.

A Variety of 

Challenges, Including 

Potential Spectrum 

Sharing, May Affect 

the Deployment

of V2I

Potential Spectrum 

Sharing

Page 18 GAO-15-775 Intelligent Transportation Systems

 
such as V2I and V2V technologies.42 FCC issued a Notice of Proposed 

Rulemaking in February 2013 that requested comments on this proposed 

solution.43

DOT officials and 17 out of 21 experts we interviewed considered the 

proposed spectrum sharing a significant challenge to deploying V2I 

technologies.44 DSRC systems support safety applications that require 

the immediate transfer of data between entities (vehicle, infrastructure, or 

other platforms). According to DOT officials, delays in the transfer of such 

data due to harmful interference from unlicensed devices may jeopardize 

crash avoidance capabilities. Experts cited similar concerns, with one 

state official saying that if they deploy applications and they do not work 

due to harmful interference, potential users may not accept V2I. Seven 

experts we interviewed agreed that further testing was needed to 

determine if sharing would result in harmful interference to DSRC. In 

addition, DOT officials noted that changing to a shared 5.9 GHz band 

could impact current V2I research, which is based on the assumption that 

DSRC systems will have reliable access to the 5.9 GHz wireless 

spectrum.

According to Japanese government officials we interviewed, Japan also 

considered whether to share its dedicated spectrum with unlicensed 

devices and decided not to allow sharing of the spectrum used for V2I in 

the 700 MHz band.45 According to officials we interviewed, Japan’s 

Ministry of Internal Affairs and Communications conducted a study to test 

interference with V2I technologies and mobile phones to determine the 

42Spectrum sharing can be defined as the cooperative use of common spectrum that 

allows disparate missions to be achieved. In this way, multiple users agree to access the 

same spectrum at different times or locations, as well as negotiate other technical 

parameters, to avoid adversely interfering with one another. For sharing to occur, users 

and regulators must negotiate and resolve where (geographic sharing), when (sharing in 

time), and how (technical parameters) spectrum will be used. GAO-13-7. 

43In the Matter of Revision of Part 15 of the Commission’s Rules to Permit Unlicensed 

National Information Infrastructure (U-NII) Devices in the 5 GHz Band, Notice of Proposed 

Rulemaking, 28 FCC Rcd 1769 (2013). 

44Two of 21 experts we interviewed did not provide a response to this question. 

45In 2001, the Japanese government dedicated the 5.8GHz band to broadcast safety 

information using DSRC, and in 2011, dedicated the 700 MHz (760 MHz) band to support 

V2I technologies.

Page 19 GAO-15-775 Intelligent Transportation Systems

 
impact on reliability and latency in delivering safety messages.46 Based 

on these tests, the Japanese government decided not to allow sharing of 

the spectrum band used for V2I, because sharing could lead to delays or 

harmful interference with V2I messages. Japanese auto manufacturers 

we interviewed in Japan supported the decision of the Japanese 

government to keep the 700 MHz band dedicated to transportation safety 

uses. According to officials, if latency problems affect the receipt of safety 

messages, this could degrade the public’s trust, consequently slowing 

down acceptance of the V2I system in Japan.

Since the Notice of Proposed Rulemaking was announced, various 

organizations have begun efforts to evaluate potential spectrum sharing 

in the 5.9 GHz band and some have expressed concerns. For example, 

harmful interference from unlicensed devices sharing the same band 

could affect the speed at which a V2I message is delivered to a driver.

NTIA, which has conducted a study on the subject, identified risks 

associated with allowing unlicensed devices to operate in the 5.9 GHz 

band, and concluded that further work was needed to determine whether 

and how the risks identified can be mitigated. DOT also plans to evaluate 

the potential for unlicensed device interference with DSRC as discussed 

below.47

Given the pending FCC rulemaking decision, DOT, technology firms, and 

car manufacturers have taken an active role pursuing solutions to 

spectrum sharing. Specifically, DOT’s fiscal year 2016 budget request 

included funds for technical analysis to determine whether DSRC can coexist with the operation of unlicensed wireless services in the same 

radiofrequency band without undermining safety applications.48 According 

to DOT officials, since industry has not yet developed an unlicensed 

device capable of sharing the spectrum, the agency does not have a 

specific date for completion of this testing at this time. DOT officials 

46In this case, latency refers to the relative response time in communications between the 

originating and the responding application components (onboard unit, roadside unit, or 

back office services) needed for the application to be effective.

47See Department of Commerce, NTIA. Evaluation of the 5350-5470 MHz and 5850-5925 

MHz Bands Pursuant to Section 6406(b) of the Middle Class Tax Relief and Job Creation 

Act of 2012 (Washington, D.C.: January 2013).

48DOT, Fiscal Year 2016 Office of Secretary Congressional Budget Justification 

(Washington, D.C.: February 2015). 

Page 20 GAO-15-775 Intelligent Transportation Systems

 
noted, however, that they would work with NTIA in any spectrum-related 

matter to inform FCC of its testing results.49 According to FCC officials we 

spoke with, FCC is currently collecting comments and data from 

government agencies, industry, and other interested parties and will use 

this information to inform their decision. For example, since 2013, 

representatives from Toyota, Denso, CSR Technology, and other firms 

worked together as part of the Institute of Electrical and Electronics 

Engineers (IEEE) DSRC Tiger Team50 to evaluate potential options and 

technologies that would allow unlicensed devices to use the 5.9 GHz 

band without causing harmful interference to licensed devices. However, 

the representatives did not reach an agreement on a unified spectrumsharing approach. Another ongoing effort from Cisco Systems, the 

Alliance of Automobile Manufacturers, and the Association of Global 

Automakers is preparing to test whether unlicensed devices using the 

“listen, detect and avoid”51 protocol would be able to share spectrum 

without causing harmful interference to incumbent DSRC operations.52 As 

of September 2015, FCC has not announced a date by which it will make 

a decision.

Because the deployment of V2I technologies will not be mandatory, the 

decision to invest in these technologies will be up to the states and 

localities that choose to use them as part of their broader trafficmanagement efforts. However, many states and localities may lack 

resources for funding both V2I equipment and the personnel to install, 

operate, and maintain the technologies. In its report on the costs, 

49NTIA works with FCC via the Policy and Plans Steering Group, as well as the Policy and 

Plans Steering Group Spectrum Working group, to foster dialogue between agencies. In 

addition to the Steering Group, DOT has submitted information through NTIA to the FCC 

as part of the public docket process.

50IEEE members are engineers, scientists, and allied professionals whose technical 

interests are rooted in electrical and computer sciences, engineering, and related 

disciplines.

51The unlicensed devices would be expected to detect and vacate bands that are being 

used by DSRC operations at that time.

52The tests are developmental in nature and designed to demonstrate and measure a 

Cisco proposal in the presence of DSRC transmitters and to ensure the technology 

operates as intended. Testing will begin in a laboratory setting and then advance to field 

tests, with the expectation that the initial round of feasibility testing will be completed by 

the end of 2015.

Lack of State and Local 

Resources to Develop and 

Maintain V2I Systems

Page 21 GAO-15-775 Intelligent Transportation Systems

 
benefits, and challenges of V2I deployment by local transportation 

agencies, the National Cooperative Highway Research Program 

(NCHRP) noted that many states they interviewed said that their current 

state budgets are the leanest they have been in years.53 Furthermore, 

states are affected because traditional funding sources, such as the 

Highway Trust Fund, are eroding, and funding is further complicated by 

the federal government’s current financial condition and fiscal outlook.54

Consequently, there can be less money for state highway programs that 

support construction, reconstruction, and improvement of highways and 

bridges on eligible federal-aid highway routes, as well as for other 

authorized purposes.55 According to one stakeholder we interviewed, 

there have been widespread funding cuts for state DOTs, and many state 

DOTs must first focus on maintaining the infrastructure and equipment 

they already have before investing in advanced technologies.56 Ten 

experts we interviewed, including six experts from state and local 

transportation agencies, agreed that the lack of state and local resources 

will be a significant challenge to deploying V2I technologies.57 According 

to one report, without additional federal funding, deploying V2I systems 

would be difficult.58

Even if states decide to invest in V2I deployment, states and localities 

may face difficulties finding the resources necessary to operate and 

maintain V2I technologies. We have previously found that effectively 

53The NCHRP is a research organization administered by the Transportation Research 

Board, and sponsored by members of AASHTO, in cooperation with FHWA. Individual 

projects are conducted by contractors with oversight provided by volunteer panels of 

expert stakeholders.

54See GAO. High-Risk Series: An Update, GAO-15-290 (Washington, D.C; February 

2015). GAO maintains a program to focus attention on government operations that it 

identifies as high risk due to their greater vulnerabilities to fraud, waste, abuse, and 

mismanagement or the need for transformation to address economy, efficiency, or 

effectiveness challenges. Funding the nation’s surface transportation system has been 

listed on our high-risk list since 2007. 

55GAO, Highway Trust Fund: All States Received More Funding Than They Contributed in 

Highway Taxes from 2005 to 2009, GAO-11-918. (Washington. D.C: September 2011).

56The stakeholder was from a transportation research organization.

57Five of 21 experts we interviewed did not provide a response to this question.

58NCHRP, Costs and Benefits of Public-Sector Deployment of Vehicle-to-Infrastructure 

Technologies, 03-101 (Washington, D.C.: 2013).

Page 22 GAO-15-775 Intelligent Transportation Systems

 
using intelligent transportation systems, like V2I, depends on agencies’

having the staff and funding resources needed to maintain and operate 

the technologies.59 However, a recently released DOT report noted that 

staffing and information technology resources for maintaining V2I 

technologies were lacking in most agencies due to low and uncompetitive 

wage rates and funding constraints at the state and local government 

levels.60 Similarly, 12 experts we interviewed stated that states and 

localities generally lack the resources to hire and train personnel with the 

technical skills needed to operate and maintain V2I systems.

According to FHWA’s draft guidance on V2I deployment, funds are 

available for the purchase and installation of V2I technologies under 

various Federal-aid highway programs.61 In addition, costs that support 

V2I systems, including maintenance of roadside equipment and related 

hardware, are eligible in the same way that other Intelligent 

Transportation System (ITS) equipment and programs are eligible. 

According to DOT, states have the authority and responsibility to 

determine the priority for funding V2I systems along with other competing 

transportation programs.

Japan’s V2I systems, which were also voluntarily deployed, were funded 

in large part by the national government. According to Japan’s National 

Police Agency, half of the costs for traffic signals were provided by the 

national government. In addition, according to the National Policy Agency, 

the Japanese government has invested an estimated $97 million (2014 

dollars) in research and development for these systems. Two of the 

Japanese automakers we interviewed attributed the success of the 

Japanese V2I system in part to the significant government involvement 

and financial investment. Furthermore, according to a study on 

international connected vehicle technologies, Japan’s nationally deployed 

59GAO, Intelligent Transportation Systems: Improved DOT Collaboration and 

Communication Could Enhance the Use of Technology to Manage Congestion, 

GAO-12-308 (Washington, D.C.: Mar. 19, 2012).

60DOT, Lessons Learned from Safety Pilot and Other Connected Vehicle Test Programs, 

(Ann Arbor, MI: May 30, 2014).

61For example, a deployment that supports V2I mobility or environmental applications may 

be eligible for funds through the Congestion Mitigation and Air Quality (CMAQ) 

Improvement Program, because these applications may provide the benefits of relieving 

traffic congestion, enhancing transit bus performance, and improving air quality.

Page 23 GAO-15-775 Intelligent Transportation Systems

 
and funded infrastructure devices allowed for industry partners to test and 

release connected vehicle technologies.62

Nineteen of the 21 experts we spoke with reported that establishing 

technical standards is essential for all connected vehicle programs, 

including V2I, and will be challenging for a number of reasons.63

According to DOT, such standards define how systems, products, and 

components perform, how they can connect, and how they can exchange 

data to interoperate.64 DOT further noted that these standards are 

necessary for connected vehicle technologies to work on different types 

of vehicles and devices to ensure the integrity and security of their data 

transmission. As well, current standardization efforts have focused on 

standardizing the data elements and message sets that are transmitted 

between vehicles and the infrastructure.65 Currently, according to DOT 

officials, DOT and various organizations have worked with the Society for 

Automotive Engineers (SAE) International to standardize the message 

sets and associated performance requirements for DSRC (SAE J2735 

and J2945), which support a wide variety of V2V and V2I applications.66

DOT, SAE International, and engineers from auto manufacturers, V2I 

suppliers, technology firms, and other firms meet to develop high-quality, 

safe, and cost-effective standards for connected vehicle devices and 

technologies, according to an expert from a leading industry organization 

specializing in setting connected vehicle technical standards. This expert 

also noted that developing consensus around what standards should be 

instituted could be difficult given the different interests (political, 

62Center for Automotive Research and the Michigan Department of Transportation, 

International Survey of Best Practices in Connected and Automated Vehicle Technologies, 

(September 26, 2014). 

63One of 21 experts we interviewed did not provide a response to this question. 

64According to DOT, it is important to note that these are not design standards; for 

example, they do not specify specific products or designs to use. 

65Before 2007, in the early development phase, DOT worked with National Institute of 

Standards and Technology on the framework for V2I standards.

66SAE International is a global association of more than 138,000 engineers and related

technical experts in the aerospace, automotive, and commercial-vehicle industries. SAE 

International is recognized as the world’s largest automotive and aerospace standardssetting body. According to SAE International, these standards are recognized as the 

foundation for safety, quality, and the effectiveness of products and services across the 

global mobility-engineering industry.

Developing Technical 

Standards to Ensure 

Interoperability of

V2I Systems

Page 24 GAO-15-775 Intelligent Transportation Systems

 
economic, or industry-related) of the many stakeholders involved in 

developing and deploying V2I technologies. For example, the expert said 

that developing effective security standards required for these 

technologies that are also cost-effective for auto manufacturers and 

government organizations to implement may be difficult.

Without common standards, V2I technologies may not be interoperable. 

DOT has noted that consistent, widely applicable standards and protocols 

are needed to ensure V2I interoperability across devices and 

applications. However, ensuring interoperability with a standard set of V2I 

applications in each state may be particularly challenging because unlike 

V2V, deployment of V2I technologies will remain voluntary. Consequently, 

states and localities may choose to deploy a variety of different V2I 

technologies—or no technologies at all—based on what they deem 

appropriate for their transportation needs. DOT officials we interviewed 

recognized that a complete national deployment67 of V2I technologies 

may never occur, resulting in a patchwork deployment of different 

applications in localities and states, although these applications will be 

required to be interoperable with one another. As a result, V2I 

deployment may be challenged by the following limitations:

• Benefits may not be optimized: Four experts we interviewed said that 

having a standard set of V2I applications in each state would be 

beneficial for drivers because a consistent deployment of applications 

could potentially increase benefits.

• Development of applications may be more limited: AASHTO’s 

National Connected Vehicle Footprint Analysis argues that the more 

connected vehicle infrastructure is deployed nationwide using 

common standards, the more likely applications will be developed to 

take advantage of new safety, mobility, and environmental 

opportunities.

• Drivers may not find the system valuable: One expert from a state 

agency said without a standard set of V2I applications that allows 

drivers to use V2I applications seamlessly as they travel from state to 

67According to the AASHTO Footprint Analysis, a mature connected vehicle environment 

by 2040 will include: (1) 80 percent (250,000) of traffic signal locations will be vehicle-toinfrastructure (V2I)-enabled; (2) up to 25,000 other roadside locations will be V2I-enabled; 

and (3) accurate, real-time, localized traveler information will be available on 90 percent or 

more of roadways.

Page 25 GAO-15-775 Intelligent Transportation Systems

 
state, travelers may lose confidence in the usefulness of the system 

and choose not to use it.

DOT and standardization organizations, such as the Society of 

Automotive Engineers (SAE) International, are working to develop 

standards to support DSRC and other V2I communications technologies. 

The data elements and message sets specified in the SAE standards are 

suitable not only for use with DSRC but also with other communications 

technologies such as cellular. According to DOT officials, the department 

is providing funding support, expert participation, and leadership in 

multiple standards development organizations to promote consensus on 

the key standards required to support nationally interoperable V2I and 

V2V technology deployments. Furthermore, the V2I Deployment 

Coalition—which includes AASHTO, the Institute of Electrical and 

Electronic Engineers, and the Institute of Transportation Engineers—

intends to lead the effort to develop and support publishing of V2I 

standards, guidelines, and test specifications to support interoperability.68

To facilitate standardization among potential state users of V2I 

technologies, FHWA is currently developing deployment guidance as 

discussed previously. According to DOT, that guidance will include 

specifications to ensure interoperability and to assist state and local 

agencies in making appropriate investment and implementation decisions 

for those agencies that will deploy, operate, and maintain V2I systems.

In addition to developing V2I standards across the United States, five 

experts we interviewed mentioned the importance of international 

harmonization for V2I technologies. Auto manufacturer experts 

recognized the importance of developing standards at both a domestic 

and international level as cars are manufactured globally. However, this is 

a challenge because international standardization organizations, including 

those in Europe and Japan, have different verification and validation 

processes than the United States, according to an auto manufacturer 

expert. 69 Furthermore, another expert noted that harmonization of 

68The Connected Vehicle Reference Implementation Architecture (CVRIA) is an initiative 

to define a multi-view system architecture to support development of full-scale connected 

vehicle deployments as well as to identify candidate interfaces for standardization. 

69Some European nations have begun testing and deploying V2I efforts. For example, as 

previously noted, the Cooperative ITS Corridor will provide warning to drivers of upcoming 

roadwork and other obstacles via V2I technologies in three countries: Netherlands, 

Germany, and Austria. 

Page 26 GAO-15-775 Intelligent Transportation Systems

 
standards is dependent on the country’s or regional government’s 

regulations, and since there are different views on the role of these 

regulations in Europe, Japan, and the United States, achieving global 

standards will be complex. According to DOT, the joint standardization of 

connected vehicle systems (V2V and V2I) is a core objective of European 

Union-U.S. cooperation on ITS, and U.S.-Japan staff exchanges have 

been invaluable in building relationships and facilitating technical 

exchange, thus creating a strong foundation for ongoing collaboration and 

research. According to DOT officials, even when identical standards are 

not viable across multiple countries or regions due to technical or legal 

differences, maximizing similarities can increase the likelihood that 

common hardware and software can be used in multiple markets, 

reducing costs and accelerating deployment. According to officials from 

one Japanese auto manufacturer we interviewed, developing a standard 

message set for V2I communications in Japan was a long and 

challenging process that took over 5 years of discussion among auto 

manufacturers.

According to DOT, for connected vehicle technologies to function safely, 

security and communications infrastructure need to enable and ensure 

the trustworthiness of messages between vehicles and infrastructure. The 

source of each message needs to be trusted and message content needs 

to be protected from outside interference or attacks on the system’s 

integrity. A DOT study70 we reviewed and the majority of the experts we 

interviewed noted that data security challenges exist and cited challenges 

that range from securing messages delivered to and from vehicle devices 

and infrastructure to managing security credentials and associated 

policies for accessing data and the system.71 Fourteen of 21 experts we 

interviewed cited securing data as a significant challenge to the 

deployment of V2I technologies.72 For example, experts from 5 states and 

one local agency that operated V2I test beds told us they were uncertain 

how vehicle and infrastructure data would be stored and secured for a 

larger deployment of V2I technologies because they have only tested V2I 

70DOT, An Approach to Communications Security for a Communications Data Delivery 

System for V2V/V2I Safety, FHWA-JPO-11-130 (Washington. D.C: November 2011).

71One of 21 experts we interviewed did not provide a response to this question.

72This included 6 of 7 experts associated with a test bed, and 8 of 14 experts that were 

not associated with a test bed. 

Data Security System

and Privacy Concerns

Page 27 GAO-15-775 Intelligent Transportation Systems

 
applications in limited, small-scale deployments.73 Most of these experts 

were also unsure whether current data security efforts could be scalable 

to a larger deployment. According to DOT officials, they are currently 

researching this area.

DOT and industry have taken steps to develop a security framework for 

all connected vehicle technologies, including V2I. DOT, along with 

automakers from CAMP, are testing and developing the Security 

Credential Management System (SCMS) to ensure the basic safety 

messages are secure and coming from an authorized device. More than 

half of the experts we interviewed expressed a variety of concerns about 

(1) the SCMS system, including whether SCMS can ensure a trusted and 

secure data exchange and (2) who will ultimately manage the system.74

To solicit input on these issues DOT launched a Request for Information 

in October 2014 to obtain feedback in developing the organizational and 

operating structure for SCMS.75 In our previous work on V2V,76 we found 

that as a part of its research on the security system, DOT had identified 

three potential models—federal, public-private, and private. We 

previously found that if a federal model were pursued, according to DOT, 

the federal government would likely pursue a service contract that would 

include specific provisions to ensure adequate market access, privacy 

and security controls, and reporting and continuity of services.77 We also 

reported that under a public-private partnership, the security system 

would be jointly owned and managed by the federal government and 

private entities. At the time of our prior report, DOT officials stated that its 

legal authority and resources have led NHTSA to focus primarily on 

working with stakeholders to develop a viable private model, involving a 

privately owned and operated security-management provider.

According to DOT officials, the agency is expanding the scope of its 

planned policy research to enable the Department to play a more active 

73One university researcher was certain that information could be stored and secured for a 

larger deployment.

74One of 21 experts we interviewed did not provide a response to this question.

75The request for information was for V2V; however, SCMS is expected to serve the same 

purpose for V2I efforts, in terms of managing security credentials. 

76GAO-14-13.

77GAO-14-13.

Page 28 GAO-15-775 Intelligent Transportation Systems

 
leadership role in working with V2V and V2I stakeholders to develop and 

prototype a private, multi-stakeholder organizational model for a V2V 

SCMS. Officials said that such a model would ensure organizational 

transparency, fair representation of stakeholders, and permit the federal 

government to play an ongoing advisory role. A central component of the 

Department’s planned policy research is the development of policies and 

procedures that could govern an operational SCMS, including minimum 

standards to ensure security and appropriately protect consumer privacy.

Currently, NHTSA is reviewing comments on the management and

organization for SCMS to inform its V2V Notice of Proposed Rulemaking, 

expected to be submitted for Office of Management and Budget review by 

the end of 2015. In addition, according to DOT’s Connected Vehicle Pilot 

Deployment Program request for proposals, participating state and local 

agencies will utilize SCMS as a tool to support deployment security, 

which will allow states, local agencies, and private sector firms an 

opportunity to test capabilities in a real-world setting. Ultimately, when 

asked about the sufficiency of SCMS, almost half of the experts we 

interviewed (10 of 21) indicated they were confident that a secure system 

for V2I could be developed.78

According to FHWA, a secure system is essential to appropriately protect 

the privacy of V2I users. Nine of the experts identified privacy as a 

significant challenge for the deployment of V2I technologies. For 

example, the public may perceive that their personal information could be 

exposed or their vehicle could be tracked using connected vehicle 

technologies.79 In a connected vehicle environment, various 

organizations—federal, state, and local agencies; academic 

organizations; and private sector firms—potentially may have access to 

data generated by V2I technologies in order to, for example, manage 

traffic and conduct research. DOT has taken some steps to mitigate 

security80 and privacy concerns related to V2V and V2I technologies. 

78One of 21 experts we interviewed did not provide a response to this question.

79One of 21 experts we interviewed did not provide a response to this question. 

80According to DOT officials, the department plans to complete an assessment of V2I 

cyber security, and use the results to address the identified vulnerabilities for the V2I 

program. In addition, DOT will provide the results of this assessment to partners that will 

need to execute these mitigation measures. Currently, DOT is at the beginning stage of 

developing cyber-security materials for state and local DOT operating agencies to address 

the risk of legacy systems connecting to CV systems. DOT officials did not provide us with 

a completion date for these efforts.

Page 29 GAO-15-775 Intelligent Transportation Systems

 
According to DOT officials, the safety message will be broadcast in a very 

limited range (approximately 300 meters) and will not contain any 

information that identifies a specific driver, owner or vehicle (through 

vehicle identification numbers or license plate or registration information).

The messages transmitted by DSRC devices (such as roadside units) in 

support of V2V and V2I technologies also will be signed by security 

credentials that change on a periodic basis (currently expected to be 

every 5 minutes) to minimize the risk that a third party could use the 

messages as a basis for tracking the location or path of a specific 

individual or vehicle.

Additionally, with respect to V2I technologies, DOT officials, car 

manufacturers and V2I suppliers plan to incorporate privacy by design 

into V2I technologies.81 Under this approach, according to DOT, V2I data 

will be aggregated, and anonymized. Also NHTSA is currently in the 

process of conducting a V2V privacy risk assessment and intends to 

publish a Privacy Impact Assessment in connection with its V2V Notice of 

Proposed Rulemaking, which is expected to include an analysis of data 

collected, transmitted, stored, and disclosed by the V2V system 

components and other entities in relation to privacy concerns. The 

Department expects the V2V privacy risk research and the Privacy Impact 

Assessment to influence the development of policies, including security 

and privacy policies with regard to V2I. Furthermore, according to DOT, 

its V2I Deployment Coalition also plans to identify privacy and data issues 

at the state and county level.

According to Japanese officials we interviewed from the Ministry of Land, 

Infrastructure, Transport, and Tourism (MLIT), Japan took a number of 

steps to address the security and privacy of its V2I system. First, Japan’s 

Intelligent Transportation Systems Technology Enhancement Association 

is responsible for managing the security of their V2I systems, and 

developed a system that used encryption to maintain security and ensure 

privacy. More specifically, each vehicle participating in V2I is assigned a 

changing, random identification number each time the vehicle started, 

81According to the Information and Privacy Commissioner of Ontario, Canada, privacy by 

design is an approach to protecting privacy by embedding it into the design specifications 

of technologies, business practices, and physical infrastructures. According to DOT, for 

V2I, this would create a security system technically designed so that it would be very 

difficult to use the system to track vehicles or individuals, or otherwise discover any 

personally identifiable information. 

Page 30 GAO-15-775 Intelligent Transportation Systems

 
thus making it difficult to track the vehicle over time. MLIT officials also 

noted that data generated from each vehicle is not stored permanently, 

but rather saved for distinct time frames depending on its use. Further, 

MLIT officials stated that security is ensured because V2I information is 

protected, anonymous, non-identifiable, and not shared with outside 

organizations; rather, it is used solely for public safety purposes. 

According to the National Police Agency officials, no significant security 

issue has occurred with V2I technologies as of July 2015.

Because V2I data will initially provide alerts and warning messages to 

drivers, the ultimate effectiveness of these technologies, especially as it 

relates to safety, depends on how well drivers respond to the warning 

messages.82 In a November 2013 report on V2V technologies, we found 

that addressing human factors that affect how drivers will respond 

included (1) minimizing the risk that drivers could become too familiar with 

or overly reliant upon warnings over time and fail to exercise due 

diligence in responding to them, (2) assessing the risk that warnings 

could distract drivers and present new safety issues, and (3) determining 

what types of warnings will maximize driver response.83 Seven of the 21 

experts we interviewed identified human factors issues as significant to 

V2I deployment.84

To address these concerns, DOT is participating in a number of research 

efforts to determine the effects of new technologies on driver distraction. 

To further examine the effects on drivers using V2I applications, NHTSA 

has a research program in place to develop human factors principles that 

may be used by automobile manufacturers and suppliers as they design 

and deploy V2I technology and other driver-vehicle interfaces that provide 

warnings to drivers.85 In addition, DOT’s ITS-JPO is funding NHTSA and 

82However, according to DOT officials, automobile manufacturers are also evaluating how 

to combine data from public infrastructure and on-board sensors in vehicles to affect 

control functions such as braking, throttling, and potentially steering to mitigate driver 

inattention or confusion. 

83GAO-14-13. The term “human factors” refers broadly to how humans’ abilities, 

characteristics, and limitations interact with the design of the equipment they use and the 

environments in which they function. 

84Two of 21 experts we interviewed did not provide a response to this question.

85DOT officials stated this was an ongoing effort and did not provide us with an estimated 

completion date.

Human Factors

Page 31 GAO-15-775 Intelligent Transportation Systems

 
FHWA research to investigate human factors implications for V2I 

technologies. Furthermore, according to DOT, the Connected Vehicle 

Pilot Program will allow additional opportunities to review drivers’

reactions to V2I messages using cameras and driver vehicle data on 

speed, braking, and other metrics.

Eleven of the 21 experts we interviewed identified uncertainty related to 

potential liability in the event of a collision involving vehicles equipped 

with V2I technologies as a challenge.86 In our November 2013 report on 

V2V, an auto manufacturer expert said that it could be harder to 

determine whether fault for a collision between vehicles equipped with 

connected vehicle technologies lies with one of the drivers, an automobile 

manufacturer, the manufacturer of a device, or another party.

According to DOT officials, it is unlikely that either V2I or V2V 

technologies will create significant liability exposure for the automotive 

industry, as DOT expects auto manufacturers will contractually limit their 

potential liability for integrated V2I and V2V applications and third-party 

services. However, according to DOT, V2I applications using data 

received from public infrastructure may create potential new liability risks 

to various infrastructure owners and operators—state and local 

governments, railroads, bridge owners, and roadway owners—because 

such cases often are brought against public or quasi-public entities and 

not against vehicle manufacturers. According to DOT, this liability will 

likely be the same as existing liability for traffic signals and variable 

message signs.

86Four of 21 experts we interviewed did not provide a response to this question.

Liabilities

Page 32 GAO-15-775 Intelligent Transportation Systems

 
DOT officials, stakeholders representing state officials and private sector 

entities, and experts we interviewed stated that the deployment of V2I 

technologies and applications is expected to result in a variety of benefits 

to users. Experts identified safety, mobility, operational, and 

environmental benefits as the potential benefits of V2I.

• Safety: Eleven of 21 experts identified safety as one of the primary 

benefits of V2I technologies.87 This included 6 of the 8 state and local 

agencies we interviewed. According to Japanese officials we 

interviewed, Japan has realized safety benefits from its deployment of 

V2I infrastructure. For example, in an effort to prevent rear-end 

collisions, Japan installed V2I infrastructure that detected and warned

motorists of upcoming congestion on an accident-prone curve on an 

expressway in Tokyo. According to Japanese officials, this combined 

with other measures such as road marking, led to a 60-percent 

reduction in rear-end collisions on this curve.

• Mobility: In interviews, 8 of 21 experts identified mobility as one of the 

primary benefits of V2I, including 6 of the 8 state and local agencies 

we interviewed.88 Officials in three states we interviewed noted that 

they are focusing on V2I applications that have the potential to 

increase mobility. These applications could allow for transportation 

system managers to identify and address congestion in real-time, as 

well as provide traffic signal priority to certain types of vehicles, such 

as emergency responders or transit. For example, Japanese officials 

estimated that as the use of electronic tolling rose to nearly 90 percent 

87Eight of the 21 experts we interviewed did not provide a response to this question.

88Eight of the 21 experts we interviewed did not provide a response to this question.

Extent of Benefits and 

Costs Are Likely to 

Remain Unclear until 

Further Deployment 

of V2I Technology

Experts Identified Potential 

Safety, Mobility, 

Operational, and 

Environmental Benefits to 

V2I Technologies, but 

Extent of Benefits Is Not 

Yet Clear

Page 33 GAO-15-775 Intelligent Transportation Systems

 
of vehicles on expressways, tollgate congestion was nearly eliminated 

on certain expressways.89

• Operations: In interviews, 7 of 21 experts, including 4 of 8 state and 

local agencies, identified the potential for V2I applications to provide 

operational benefits or cost savings.90 For example, one state agency 

noted that using data collected from vehicles could allow the 

transportation managers to more easily monitor pavement conditions 

and identify potholes (typically a costly and resource-intensive 

activity). DOT and the National Cooperative Highway Research 

Program91 have also noted that the visibility and enhanced data on 

current traffic and road conditions provided by V2I applications would 

provide operational benefits to state and local transportation 

managers. This result, in turn, could provide safety or other benefits to 

drivers. For example, officials in Japan told us that by using data 

collected from vehicles through the ITS infrastructure, they were able 

to identify 160 locations in which drivers were braking suddenly. After 

investigating the cause, officials took steps to address safety issues at 

these sites (such as trimming trees that created visual obstructions) 

and incidents of sudden braking decreased by 70 percent and 

accidents involving injuries or fatalities decreased 20 percent. In 

addition, the Japanese government partnered with private industry to 

collect and analyze vehicle probe data to help the public determine 

which roads were passable following an earthquake.

• Environment: Of the experts we interviewed, 4 of 21 identified 

environmental benefits as a primary benefit of V2I technologies, with 

some noting interconnections among safety, mobility, and 

environmental benefits.92 For example, officials from two state 

agencies we interviewed stated that improving safety and mobility will 

lead to environmental benefits because there will be less stop-and-go 

traffic. Indeed, Japanese officials estimated that decreased tollgate 

89Specifically, Japan estimates that congestion on the Metropolitan Expressway, located 

in Tokyo, was reduced from 56.2 kilometers/hour/day in 2003 to 2.8 kilometers/hour/day in 

2007, with a respective rise in electronic toll usage from 6.1 percent to 73 percent of 

vehicles.

90Eight of the 21 experts we interviewed did not provide a response to this question.

91Transportation Research Board National Cooperative Highway Research Program, 

Costs and Benefits of Public-Sector Deployment of Vehicle-to-Infrastructure Technologies, 

NCHRP 03-101 (Reston, VA: 2013).

92Eight of the 21 experts we interviewed did not provide a response to this question.

Page 34 GAO-15-775 Intelligent Transportation Systems

 
congestion reduced CO2 emissions by approximately 210,000 tons 

each year.

Although V2I applications are being developed for the purpose of 

providing safety, mobility, operational, and environmental benefits, the 

extent to which V2I benefits will be realized is currently unclear because 

of the limited data available and the limited deployment of V2I 

technologies. To date, only small research deployments have occurred to 

test connected vehicle technologies. However, DOT has commissioned or 

conducted some studies to estimate potential V2I benefits, particularly 

with respect to safety and the environment.

• NHTSA used existing crash data and estimated that in combination, 

V2V and V2I could address up to 81 percent of crashes involving 

unimpaired drivers.93 Similarly, in 2012, a study commissioned by 

FHWA used existing crash data and estimated the number, type, and 

costs of crashes that could be prevented by 12 different V2I 

applications. This study estimated that the 12 V2I applications would 

prevent 2.3-million crashes annually (representing 59 percent of 

single vehicle crashes and 29 percent of multi-vehicle crashes and 

comprising $202 billion in annual costs).94

• With respect to the environment, DOT contracted with Booz Allen 

Hamilton to develop an initial benefit-cost analysis for its 

environmental applications, with the goal of informing DOT’s future 

work and prioritization of certain applications.95 As part of the next 

phase of this work, Booz Allen Hamilton used models to estimate 

93U.S. Department of Transportation, National Highway Traffic Safety Administration, 

Frequency of Target Crashes for IntelliDrive Safety System, DOT-HS-811-381 

(Washington, D.C.: October 2010). 

94U.S. Department of Transportation, Federal Highway Administration, Crash Data 

Analyses for Vehicle-to-Infrastructure Communications for Safety Applications, FHWAHRT-11-040 (McLean, VA: November 2012). This statistic is based on assumptions 

including full deployment and 100 percent effectiveness of applications.

95U.S. Department of Transportation, AERIS: Applications for the Environment: Real-Time 

Information Synthesis Identification and Evaluation of Transformative Environmental 

Applications and Strategies Project, Initial Benefit-Cost Analysis, (Washington, DC: 

September 30, 2012). 

Page 35 GAO-15-775 Intelligent Transportation Systems

 
potential benefits of individual applications, as well as their benefits 

when used in combination with other applications.96

• NCHRP estimated operational and financial benefits that V2I 

applications may provide to state and local governments, such as 

reduced costs for crash response and cleanup costs; reduced need 

for traveler information infrastructure; reduction of infrastructure 

required to monitor traffic; and lower cost of pavement condition 

detection.97 However, one of the study’s major conclusions was that 

the data required to quantify benefits are generally not available.

• DOT is taking some steps to evaluate the benefits of V2I applications. 

For example, as part of its upcoming Connected Vehicle Pilot 

Deployment Program, pilot projects are expected to develop a 

performance-monitoring system, establish performance measures, 

and collect relevant data. Projects will also receive an independent 

evaluation of their projects’ costs and benefits; user acceptance and 

satisfaction; and lessons learned.

In addition, organizations researching the benefits of V2I have noted that 

the benefits of V2I deployments may depend on a variety of factors, 

including the size and location of the deployment, the number of roadside 

units deployed, the number of vehicles equipped, and the types of 

applications that are deployed. A study sponsored by the University of 

Michigan Transportation Research Institute noted that some V2I safety 

applications require a majority of vehicles to be equipped before reaching 

optimum effectiveness, in contrast to mobility, road weather, and 

operations applications, which only require a small percentage of 

equipped vehicles before realizing benefits.98 Japanese government 

officials, as well as representatives from a private company we 

96According to DOT officials, reports with the results of these models are underway and 

unpublished; however, they did provide us with copies of the current versions of the 

reports. 

97Transportation Research Board National Cooperative Highway Research Program, 

Costs and Benefits of Public-Sector Deployment of Vehicle-to-Infrastructure Technologies, 

NCHRP 03-101 (Reston, VA: 2013). 

98For example, the study cited other studies that found that agencies using probe data 

from vehicles (for example, data from vehicles that provide insight into traffic or pavement 

conditions), could collect reliable data with a 5 to 10 percent penetration rate among 

vehicles. University of Michigan Transportation Research Institute, Connected Vehicle 

Infrastructure Deployment Considerations: Lessons Learned from Safety Pilot and Other 

Connected Vehicle Test Programs, (Ann Arbor, MI: May 30, 2014).

Page 36 GAO-15-775 Intelligent Transportation Systems

 
interviewed in Japan, noted that in some cases, they have found it difficult 

to quantify benefits. However, DOT and the Ministry of Land, 

Infrastructure, Transport and Tourism of Japan established an Intelligent 

Transportation Systems (ITS) Task Force to exchange information and 

identify the areas for collaborative research to foster the development and 

deployment of ITS in both the United States and Japan. According to 

DOT, evaluation tools and methods are high-priority areas for the task 

force, and DOT has stated that a report detailing the task force’s 

collaborative research on evaluation tools and methods will be published 

in 2015. In addition, 8 of the 21 experts we interviewed noted that it can 

be difficult to identify benefits that are solely attributable to V2I, due to the 

interconnected nature of V2V and V2I technologies.99 However, some 

experts we spoke with provided some examples of how connected 

vehicle benefits could be measured, including: crash avoidance, reduction 

in fatalities, reduced congestion, and reduced travel times.

The costs for the deployment of a national V2I system are unclear 

because current cost data for V2I technology are limited due to the small 

number of test deployments thus far. According to DOT officials, experts, 

and other industry stakeholders we spoke to, there are two primary 

resources for estimating V2I deployment costs: AASHTO’s National 

Connected Vehicle Footprint Analysis (2014) and National Cooperative 

Highway Research Program’s (NCHRP)100 03-101 Costs and Benefits of 

Public-Sector Deployment of Vehicle-to-Infrastructure Technologies

(2013).101 However, the cost estimates in both reports are based on 

limited available data from small, research test beds. As a result, neither 

report contains an estimate for the total cost if V2I were to be deployed at 

99Eight of the 21 experts we interviewed did not provide a response to the question about 

quantifying V2I benefits apart from V2V benefits.

100The NCHRP is a research organization administered by the Transportation Research 

Board and sponsored by members of AASHTO, in cooperation with FHWA. Individual 

projects are conducted by contractors with oversight provided by volunteer panels of 

expert stakeholders.

101We use both the NCHRP and the AASHTO reports to provide global statements about 

potential costs, but we will only be using cost figures from the AASHTO report as it 

contains the most recent information on potential, average estimates and is being used by 

DOT for the basis of cost estimation tools. 

The Costs for V2I

Are Unclear due to

Limited Deployment

Page 37 GAO-15-775 Intelligent Transportation Systems

 
a national level.102 Despite these limitations, the cost estimates in these 

two studies are cited by several experts and industry stakeholders, 

including DOT.103 According to DOT, these cost figures may be useful to 

agencies considering early deployments.

According to AASHTO and NCHRP, costs of V2I deployment will likely be 

comprised of two types of costs. First, V2I will require non-recurring

costs—the upfront, initial costs required to deploy the infrastructure.

According to AASHTO, there are two primary, non-recurring cost 

categories associated with V2I deployments:

• Infrastructure deployment costs include the costs for planning, 

acquiring, and installing the V2I roadside equipment. State and local 

agencies will need to evaluate the costs for planning and design that 

may include mapping intersections and deciding where to deploy the 

DSRC radios based on traffic and safety analyses, according to 

AASHTO. Deployment costs will include the cost of acquiring the 

equipment, including the roadside unit. AASHTO estimates that the 

total equipment costs would be $7,450 per site,104 with $3,000 

attributed to each roadside unit, on average.105 However, 4 of the 

experts we interviewed stated that the cost estimates for the hardware 

are likely to decrease over time, as the technology matures and the 

market becomes more competitive. The total average cost for 

installation of the equipment per site includes the costs of labor and 

inspection. In addition, deployment costs may include the cost of 

102During development of the “National Connected Vehicle Field Infrastructure Footprint 

Analysis (FHWA-JPO-14-125),” there was an effort to develop an estimate for the total 

cost of deploying V2I systems on a national level, using the anticipated deployment costs, 

locations and timelines. However, according to DOT officials, the uncertainties in the cost 

elements are so significant that it was not deemed appropriate to generate an estimated 

cost for deploying V2I systems on a national level.

103Nine experts and five stakeholders mentioned one or both of the reports’ cost

estimates.

104“Per site” refers to each specific location where a roadside unit is deployed. For 

example, a unit could be deployed at an intersection. The “per site” costs would be 

multiplied by the number of units required by the region.

105In a connected vehicle environment, there will also be costs for the on-board 

equipment. NHTSA conducted an assessment of preliminary V2V costs and estimated 

that the total cost per vehicle will be approximately $341 to $350 in 2020, decreasing to 

$209 to $227 in 2058.

Page 38 GAO-15-775 Intelligent Transportation Systems

 
upgrading traffic signal controllers.106 AASHTO estimates that 

approximately two thirds of all controllers in the United States will 

need to be upgraded to support connected vehicle activities.

• Backhaul costs refer to the costs for establishing connectivity for 

communication between roadside units and back offices or traffic 

management centers (TMCs).107 As discussed, backhaul includes the 

fiber optic cables connecting traffic signals to the back office, as well 

as any sensors or relays that link to or serve these components. 

According to NCHRP, backhaul will be one of the biggest components 

of costs. In fact, three state agencies and one supplier we spoke with 

referred to backhaul as a factor that will affect costs for V2I 

deployment. Backhaul costs are also uncertain because states vary in 

the extent to which they have existing backhaul. According to 

AASHTO, some sites may only require an upgrade to their current 

backhaul system to support expected bandwidth requirements for 

connected vehicle communications. However, 40 percent of all traffic 

signals have either no backhaul or will require new systems, 

according to AASHTO. The difference in cost between tying into an 

existing fiber-optic backhaul and installing a new fiber-optic backhaul 

for the sites is significant, according to DOT. The average national 

cost to upgrade backhaul to a DSRC roadside site is estimated to vary 

from $3,000, if a site has sufficient backhaul and will only need an 

upgrade, to $40,000, if the V2I site requires a completely new 

backhaul system, according to AASHTO estimates.

The total potential average, non-recurring costs of deploying connected 

vehicle infrastructure per site, according to DOT and AASHTO, are 

$51,650 (see table 1).108

106Traffic signal controllers provide information on the signal phase (green, yellow, or red) 

and the amount of time remaining until the light changes to the DSRC radio, which then 

broadcasts the information to the vehicle.

107As previously mentioned, backhaul is the closed network communication links between 

back offices (or TMCs) and field installations (such as traffic signal controllers). 

108According to DOT officials, these costs are based on limited, research installations, and 

are not necessarily reflective of planned deployments. Furthermore, as agencies renovate 

or upgrade existing systems (such as periodic replacement of traffic signal systems), they 

are already installing components necessary to support V2I deployments, such as fiber 

optic backhaul for the modern traffic signal controllers.

Page 39 GAO-15-775 Intelligent Transportation Systems

 
Table 1: Total Potential Average, Non-Recurring Costs of Connected Vehicle 

Infrastructure per Site

Cost element Average cost 

Planning and design average costs $6,650

Equipment average costs $7,450

Installation average costs $3,550

Backhaul average costs $30,800

Signal controller upgrades average costs $3,200

Total potential average costs per site $51,650

Source: American Association of State Highway and Transportation Officials and DOT, | GAO-15-775

Note: “Per site” refers to each specific location where a roadside unit is deployed.

Second, V2I will also require recurring costs—the costs required to 

operate and maintain the infrastructure. According to AASHTO, there are 

several types of recurring costs associated with V2I deployments, 

including equipment maintenance and replacement, security, and 

personnel costs. The amount of maintenance needed to keep roadside 

units running is unclear, according to 3 of the experts we interviewed, 

because the test bed deployments have generally not operated long 

enough to warrant maintenance of the equipment. However, NCHRP 

estimates that routine maintenance costs for roadside units would likely 

vary from 2 to 5 percent of the original hardware and labor costs. This 

includes such maintenance as realigning antennas and rebooting 

hardware. AASHTO also estimates that the device would need replacing 

every 5 to 10 years. In addition, states and localities may also need to 

hire new personnel or train existing staff to operate these systems. 

According to AASHTO, personnel costs will also depend on the size of 

the deployment as smaller deployments may not need dedicated 

personnel to complete maintenance, while large deployments may require 

staff dedicated to system monitoring on site or on call. Furthermore, 

security costs will be a recurring cost and include the costs of keeping the 

security credentials of the SCMS up to date and the costs to manage the 

security system, according to AASHTO. Given that SCMS is still being 

developed, cost estimates are unknown.109 One car manufacturer we 

interviewed explained that because the management of the security 

system is unknown, it is extremely challenging to estimate future costs. In 

109In its report, AASHTO assumes a cost of $50 per device to develop a more accurate 

estimate of the annual operating costs.

Page 40 GAO-15-775 Intelligent Transportation Systems

 
addition, one county agency official said security costs could greatly affect 

the total costs for V2I deployment because the requirements and funding 

responsibility are not clearly defined. As part of its ANPRM, NHTSA 

conducted an assessment of preliminary V2V costs, including costs for 

the SCMS.110 NHTSA estimated that the SCMS costs per vehicle range 

from $1 to $6, with an average of $3.14. SCMS costs will increase over 

time due to the need to support an increasing number of vehicles with the 

V2V technologies, according to NHTSA.

While AASHTO and NCHRP have estimated the above potential average 

costs for various components associated with a V2I deployment, 10 of 21 

experts stated that it is difficult to determine the actual costs for a V2I 

deployment in a particular state or locality due to a number of factors.111

• First, the scope of the deployment will affect the total costs of a 

region’s V2I deployment, according to NCHRP, because it will 

determine the amount of equipment needed for the system to 

function, including the number of roadside units. Previous test bed 

deployments have varied in size ranging from 1 to 2,680 DSRC 

roadside units. Further, the number of devices needed will be 

dependent on how many devices are required to enable the 

applications. For example, while a curve-speed-warning application 

may require installing equipment at a specific location, applications 

that aim to mitigate congestion by advising drivers of the best speed 

to approach an intersection may need to be installed at several 

intersections throughout an urban corridor. One state agency said that 

one factor that could affect costs is how often roadside equipment 

needs to be replaced in order to enable certain V2I applications. In 

addition, as previously mentioned, the size of the deployment will 

contribute to personnel costs.

• Second, the state or locality’s deployment environment will affect its 

deployment costs. One state agency pointed out that everyone’s costs 

will be different because they will be deploying in environments with 

differing levels of existing infrastructure. For example, as previously 

noted, the region’s existing backhaul infrastructure will determine the 

extent of the cost for installing or upgrading the region’s system, 

11079 Fed. Reg. 49270 (Aug.20, 2014).

111Seven of the 21 experts we interviewed did not provide a response to this question.

Page 41 GAO-15-775 Intelligent Transportation Systems

 
including whether a city or state has fiber optics already installed or 

signal controllers need upgrading.

• Lastly, the maturity of the technology will also affect cost estimates for 

equipment such as a DSRC radio. Estimating equipment costs is 

difficult at this time because the technology is still developing, 

according to NCHRP. Ten of the 21 experts we interviewed, including 

all of the state agencies, also mentioned that estimating costs is 

challenging because the technology is still immature.112 Furthermore, 

the reports and 4 experts we interviewed agree that the cost 

estimates for the hardware are likely to decrease over time, as the 

technology matures and the market becomes more competitive. 113

As part of the upcoming Connected Vehicle Pilot Deployment Program, 

DOT developed the Cost Overview for Planning Ideas and Logical 

Organization Tool (CO-PILOT). This tool generates high-level cost 

estimates for 56 V2I applications based on AASHTO’s estimations. In 

addition, according to DOT, the agency will work with AASHTO to 

develop a life-cycle cost tool that agencies can use to support V2I 

deployment beyond the Connected Vehicle Pilot Deployment Program. 

DOT officials also indicated that they plan to update the tool over time as 

more data are collected from the Connected Vehicle Pilot Deployment 

Program, and they expect the tool to be available for use by 2016. Also, 

as previously mentioned, FHWA is developing deployment guidance that 

will outline potential sources of funding for states and localities, among 

other things.

We provided a draft of this product to the Secretary of Transportation, 

Secretary of Commerce, and the Chairman of the FCC, for review and 

comment. DOT and Commerce’s NTIA both provided comments via email 

that were technical in nature. We incorporated these comments as 

appropriate. FCC did not provide comments.

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. We will send copies of this report to the Secretary of 

112Seven of the 21 experts we interviewed did not provide a response to this question.

113Five of the 21 experts we interviewed did not provide a response to this question.

Agency Comments

Page 42 GAO-15-775 Intelligent Transportation Systems

 
Transportation, the Chairman of the Federal Communications 

Commission, and the Administrator of the National Telecommunications 

and Information Administration and appropriate congressional 

committees. In addition, the report will be available at no charge on the 

GAO website at http://www.gao.gov.

If you or your staff have any questions about this report, please contact 

me at (202) 512-2834 or wised@gao.gov. Contact points for our Offices 

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

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

are listed in appendix III.

David Wise

Director, Physical Infrastructure

Page 43 GAO-15-775 Intelligent Transportation Systems
Appendix I: Scope and Methodology

To address all of our objectives, we reviewed documentation relevant to 

vehicle-to-infrastructure (V2I) technology research efforts of the 

Department of Transportation (DOT), state and local government, and 

automobile industry, such as DOT’s 2015 Federal Highway Administration 

V2I Draft Deployment Guidance and Products and AASHTO’s National 

Connected Vehicle Field Infrastructure Footprint Analysis, as well as 

documentation on completed and ongoing research. We interviewed 

officials from DOT’s Office of the Assistant Secretary for Research and 

Technology, Intelligent Transportation Systems-Joint Program Office 

(ITS-JPO), Federal Highway Administration (FHWA), National Highway 

Traffic Safety Administration (NHTSA), and the Volpe National 

Transportation Systems Center, about these efforts.

For all objectives, we developed a structured set of questions for our 

interviews with 21 experts who represented domestic automobile 

manufacturers, V2I device suppliers, state and local government, privacy 

experts, standardization organizations, and academic researchers with 

relevant expertise. The identified experts have varying degrees of 

expertise in the following areas related to V2I technology: the production 

of passenger vehicles; technology development; technology deployment; 

data privacy; security; state agency deployment; and legal and policy 

issues. Our starting point for our expert selection was a list of experts 

originally created in January 2013 by the National Academy of Sciences 

for GAO’s vehicle-to-vehicle (V2V) report.1 We used this list for our initial 

selection because V2V and V2I technologies are both connected vehicle 

technologies with many similarities, and many V2V stakeholders are also 

working on V2I.2 In addition to nine experts we selected from the National 

Academy of Sciences list, we selected an additional 12 experts based on 

the following factors:

1

GAO, Intelligent Transportation Systems: Vehicle-to Vehicle Technologies Expected to 

Offer Safety Benefits, but a Variety of Deployment Challenges Exist, GAO-14-13

(Washington D.C.: November 2013) 

2

Connected vehicle technologies involve vehicle-to-vehicle (V2V) and vehicle-toinfrastructure (V2I) technologies. V2V is a system designed to transmit basic safety 

information between vehicles to facilitate warnings to drivers about potential collisions. V2I 

is defined as the wireless exchange of safety and operational data between vehicles and 

roadside infrastructure, intended primarily to avoid or mitigate motor vehicle crashes.

Appendix I: Scope and Methodology

Page 44 GAO-15-775 Intelligent Transportation Systems

 
Appendix I: Scope and Methodology

1. their personal involvement in the deployment of V2I technologies;

2. recommendations from federal agencies (DOT, and the Federal 

Communications Commission (FCC) and associations (such as the 

American Association of State and Highway Transportation Officials 

(AASHTO); and

3. experts’ involvement in professional affiliations such as a V2I 

consortium or groups dedicated to these technologies or to a specific 

challenge affecting V2I (e.g., privacy).

Table 2 lists the experts we selected.

In conducting our structured interviews, we used a standardized interview 

to ensure that we asked all of the experts the same questions. During 

these interviews we asked, among other things, for expert views on the 

state of development and deployment of V2I technologies (including 

DOT’s role in this process), the potential benefits of V2I technologies, and 

their potential costs. We also asked for each expert’s views on a number 

of defined potential challenges facing the deployment of V2I technologies, 

and asked the experts to rate the significance of each challenge using a 

three-point scale (significant challenge, moderate challenge, or slight 

challenge). We determined this list of potential challenges after initial 

interviews with DOT, industry associations, and other interest groups 

knowledgeable about V2I technologies. Prior to conducting the interviews, 

we tested the structured interview with one association to ensure our 

questions were worded appropriately. After conducting these structured 

interviews, we summarized expert responses relevant to each objective. 

The viewpoints gathered through our expert interviews represent the 

viewpoints of individuals interviewed and cannot be generalized to a 

broader population.

Page 45 GAO-15-775 Intelligent Transportation Systems
Appendix I: Scope and Methodology

Table 2: Subject Matter Experts Interviewed

Experts Organization

Roger Berg Denso

Debra Bezzina University of Michigan Transportation Research Institute

Dorothy Glancy Santa Clara University School of Law

Michael Shulman Ford and Crash Avoidance Metrics Partners, LLC

Tom Schaffnit Vehicle Infrastructure Integration Consortium

Ravi Puvvala Savari Networks

David Miller Siemens

Barry Einsig Cisco

Jack Pokrzywa SAE International

Siva R.K. Narla Institute of Transportation Engineers

Scott Geisler General Motors

Steven Siko Chrysler

Jules Polonetsky Future for Privacy Forum

Greg Larson California Department of Transportation

Richard McDonough New York State Department of Transportation

Matt Smith Michigan Department of Transportation

Catherine McGhee Virginia Department of Transportation

Elizabeth Birriel Florida Department of Transportation

Charlie Farnham Texas Department of Transportation

Blaine Leonard Utah Department of Transportation

Faisal Saleem Maricopa County Department of Transportation, Arizona

Source: GAO. | GAO-15-775

For the purpose of this review, state and local agency officials were 

considered experts because of their experience in deploying and testing 

V2I technologies, and experience working with the required technologies 

(DSRC equipment and software), decision process (funding and 

scheduling); personnel requirements and skill sets needed for 

deployment; operations and maintenance. We specifically included six 

officials who deployed V2I test beds in their respective states in our pool 

of expert interviews.

We also included two officials who studied V2I for several years, had 

taken part in the AASHTO’s Connected Vehicle group, and had applied to 

DOT’s prior Connected Vehicles Pilot Program (V2I test bed). We also 

interviewed additional officials who have contributed to the U.S. efforts to 

develop and deploy connected vehicle technologies—officials who we 

Page 46 GAO-15-775 Intelligent Transportation Systems
Appendix I: Scope and Methodology

refer to as “stakeholders.” Specifically, we used these stakeholders to 

help us understand issues that informed our structured set of questions, 

but did not administer the structured question set during these 

stakeholder interviews. We primarily selected stakeholders based on 

recommendations from DOT and industry associations. However, we also 

included DOT as a stakeholder in the deployment of V2I technologies 

because it is leading federal V2I efforts.

We interviewed officials from 17 V2I stakeholder organizations including: 

1. DOT, NHTSA 

2. DOT, Office of the Assistant Secretary for Research and Technology,

ITS-JPO

3. DOT, FHWA 

4. DOT, Volpe National Transportation Systems Center

5. DOT, Chief Privacy Officer

6. National Telecommunications and Information Administration (NTIA) 

7. FCC 

8. AASHTO 

9. Intelligent Transportation Society of America (ITS America) 

10. Crash Avoidance Metrics Partners, LLC (CAMP) 

11. Institute of Electrical and Electronics Engineers (IEEE) 

12. National Cooperative Highway Research Program (NCHRP)

13. Leidos, previously known as Science Applications International 

Corporation (SAIC)

14. Virginia Tech Transportation Institute

15. Virginia Department of Transportation

16. Minnesota Department of Transportation

17. Road Commission for Oakland County, Michigan

To determine the status of development and deployment of V2I 

technology, we interviewed officials from DOT, including the Office of the 

Assistant Secretary for Research and Technology, ITS-JPO, FHWA, 

Page 47 GAO-15-775 Intelligent Transportation Systems
Appendix I: Scope and Methodology

Volpe National Transportation Systems Center, and the NHTSA. We also 

interviewed officials at all seven V2I test beds located in Virginia, 

Michigan, Florida, Arizona, California, and New York.3 We conducted site 

visits to three test beds—the Safety Pilot in Ann Arbor, Michigan, and the 

test beds in Southeast Michigan and Northern Virginia. We selected the 

three site visit locations based on which had the most advanced 

technology according to DOT and state officials. At these site visits, we 

conducted interviews with officials from state and local transportation 

agencies and academic researchers to collect information on developing 

and deploying V2I technology. We visited FHWA’s Turner Fairbank 

Highway Research Center in Virginia to understand the agency’s 

connected vehicle research efforts. We reviewed documentation of the 

efforts of DOT and automobile manufacturers related to vehicle-toinfrastructure (V2I) technologies, such as the 2015 FHWA’s V2I Draft 

Deployment Guidance and Products and documentation on completed 

and ongoing research. We identified materials published in the past 4 

years that were related to the terms “vehicle-to-infrastructure” and “V2I”

through searches of bibliographic databases, including Transportation 

Research International Documentation and WorldCat. While a variety of 

V2I technologies exist for transit and commercial vehicles, for the purpose 

of this report we limited our scope to passenger vehicles since much of 

DOT’s connected vehicle work is focused on passenger vehicles.

To determine the challenges affecting the deployment of V2I technology 

and DOT’s existing or planned actions to address potential challenges, 

we reviewed FHWA’s V2I draft guidance to assist in planning for future 

investments and deployment of V2I systems. In addition, we interviewed 

officials from FCC and NTIA about challenges related to the potential for 

spectrum sharing in the 5.9 GHz band. We interviewed DOT’s Privacy 

Officer, two privacy experts, and several stakeholders to understand 

privacy concerns regarding the deployment of V2I technologies.

We collected information on anticipated benefits of these technologies 

through interviews with officials from DOT, automobile manufacturers, 

industry associations, and experts identified by National Academy of 

Sciences and other stakeholders, and through reviews of studies they 

provided. To specifically address the potential costs associated with V2I 

3

There are two test beds in Michigan, the Safety Pilot in Ann Arbor, Michigan, and in 

Southeast Michigan, in Oakland County.

Page 48 GAO-15-775 Intelligent Transportation Systems

 
Appendix I: Scope and Methodology

technologies, we analyzed two reports, AASHTO’s National Connected 

Vehicle Field Infrastructure Footprint Analysis and NCHRP’s 03-101, Cost 

and Benefits of Public-Sector Deployment of Vehicle-to-Infrastructure 

Technologies report, both of which addressed acquisition, installation, 

backhaul, operations, and maintenance costs.4 According to DOT officials 

and other stakeholders we interviewed, those two reports were the 

primary sources of information for V2I potential deployment costs 

estimates and actual costs.5 We used V2I costs estimates from the 

AASHTO Footprint Analysis to give examples of potential costs for 

deployment. To further assess the reliability of the cost estimates, in 

addition to our own review of the two reports, our internal economic 

stakeholder also independently reviewed both reports, and we 

subsequently interviewed representatives from AASHTO and NCHRP to 

verify the scope and methodology of the cost analyses performed in both 

reports. In addition, we discussed estimated costs and factors that 

affected costs for V2I investments with experts and stakeholders from 

federal, local, state government, academia, car manufacturers, industry 

associations, and V2I suppliers. We determined that the actual cost 

figures were reliable and suitable for the purpose of our report.

In addition to the above work, we selected Japan for a site visit because 

of its nationwide deployment and years of experience with deployment 

and maintenance of V2I technologies. Japan has led efforts in V2I 

technology development and deployment for over two decades. The 

country serves as an illustrative example from which to draw information 

on potential benefits, costs, and challenges of deploying V2I technologies 

in the United States.6 During our site visit, we interviewed Japanese 

government officials and auto manufacturers on similar topics that we 

discussed with U.S. experts, including V2I deployment efforts, benefits, 

costs, and challenges.

4

AASHTO, AASHTO National Connected Vehicle Field Infrastructure Footprint Analysis,

(Washington, D.C.: June 27, 2014) and National Cooperative Highway Research Program 

(NCHRP), Cost and Benefits of Public-Sector Deployment of Vehicle-to-Infrastructure 

Technologies, 03-101 (Washington. D.C.: 2013).

5

However, it should be noted that these reports are limited in their scope because their 

findings are based on small, connected vehicle infrastructure deployments to date. 

6

Although there are V2I efforts underway in Europe, we focused on Japan due to its 20 

years of experience in developing and deploying V2I technologies.

Page 49 GAO-15-775 Intelligent Transportation Systems

 
Appendix I: Scope and Methodology

Japanese Government

• Cabinet Secretariat (IT Strategy)

• Cabinet Office (Council for Science and Technology Policy)

• Ministry of Land, Infrastructure, Transport and Tourism (MLIT)

o Road Bureau

o Road Transport Bureau

• Ministry of Internal Affairs and Communications (MIC)

• National Police Agency (NPA)

• Ministry of Economy, Trade and Industry (METI)

Car Manufacturers

• Toyota

• Honda

• Nissan

V2I Supplier

• Denso

We conducted this performance audit from July 2014 through September

2015 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.

Page 50 GAO-15-775 Intelligent Transportation Systems
Appendix II: Expert Ratings of Potential 

Challenges Facing Deployment of Vehicle-toInfrastructure Technologies

As part of our review, we conducted 21 structured interviews with 

individuals identified by the National Academy of Sciences and based on 

other factors discussed in our scope and methodology to be experts on 

vehicle-to-infrastructure (V2I) technologies (see table 2 in app. I for list of 

experts interviewed). During these interviews we asked, among other 

things, for each expert’s views on a number of already defined potential 

challenges facing the deployment of V2I technologies. The ratings 

provided by the experts for each of the potential challenges discussed are 

shown in table 3 below. To inform our discussion of the challenges facing 

the deployment of V2I technologies, we considered these ratings as well 

as experts’ responses to open-ended questions.

Table 3: Expert Ratings of Potential Challenges Facing Deployment of Vehicle-to-Infrastructure Technologies 

Potential Challenges

Significant 

Challenge

Moderate 

Challenge 

Slight 

Challenge

Did Not 

Answer

Spectrum sharing—allowing unlicensed devices to operate in the 

5.9 GHz band along with V2I technologies

17 1 1 2

Non-mandatory, voluntary deployment of V2I technologies among 

states and localities

12 6 1 2

Limitations at the federal level for V2I deployment in terms of 

funding or providing technical resources to state/local transportation 

operators

9 2 3 7

Limitations at the state/local level for V2I deployment (for example, 

funding, personnel, or other areas)

10 6 0 5

Ensuring privacy under a system that involves the sharing of data 

among vehicles and government infrastructure.

9 5 6 1

Data Security measures are in place to secure the data that is 

collected at the Test Bed [Question for Test Bed locations only] a

(Total = 7)

6 1 0 0

Ensuring data security in deploying V2I technologies. [Question for 

a non-test bed interviews—car manufacturers, associations, and 

others] a

(Total = 14)

8 3 2 1

Standardization 7 8 5 1

Human factors in the deployment of V2I technologies 7 10 2 2

Liability issues, in terms of uncertainty related to legal responsibility 

for vehicle crashes using V2I technology

5 7 5 4

Source: GAO analysis of expert interviews. | GAO-15-775

a

We asked separate data security questions depending on whether the expert had previously or 

currently worked on a V2I test bed.

Appendix II: Expert Ratings of Potential 

Challenges Facing Deployment of Vehicleto-Infrastructure Technologies

Page 51 GAO-15-775 Intelligent Transportation Systems
Appendix III: GAO Contact and Staff 

Acknowledgments

David Wise at (202) 512-2834 or at wised@gao.gov

In addition to the contact named above, Susan Zimmerman, Assistant 

Director; Nelsie Alcoser; David Hooper; Crystal Huggins; Amber Keyser; 

Nancy Santucci; Terence Lam; Josh Ormond; Amy Rosewarne; and 

Elizabeth Wood made key contributions to this report.

Appendix III: GAO Contact and Staff 

Acknowledgments

GAO Contact:

Staff 

Acknowledgments:

(542235) Page 52 GAO-15-775 Intelligent Transportation Systems
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