Abstract

While America’s transportation system continues to be one of the nation’s greatest achievements and is the lifeblood of the U.S. economy, critical improvements are needed to make surface transportation safer, smarter, and greener and ultimately enhance livability for Americans. Part of this transformation to our transportation system can be achieved through connectivity. Connected vehicles have the potential to transform the way Americans travel through the creation of a safe, interoperable wireless communications network that includes cars, buses, trucks, trains, traffic signals, cell phones, and other devices. Like the Internet, which provides information connectivity, connected vehicle technology provides a starting point for transportation connectivity that will potentially enable countless applications and spawn new industries.

Connected vehicle applications provide connectivity:

• Among vehicles to enable crash prevention
• Between vehicles and the infrastructure to enable safety, mobility, and environmental benefits
• Among vehicles, infrastructure, and wireless devices to provide continuous real-time connectivity to all system users.

A connected vehicle network can vastly improve our nation’s transportation system in the areas of safety, mobility, and environment. This paper provides an overview of connected vehicle technology and describes the U.S. Department of Transportation’s role in connected vehicle research, recent developments, and policy implications.

1.0 Connected Vehicle Overview

While America’s transportation system continues to be one of the nation’s greatest achievements and is the lifeblood of the U.S. economy, critical improvements are needed to make surface transportation safer, smarter, and greener and ultimately enhance livability for Americans. Part of this transformation to our transportation system can be achieved through connectivity. Connected vehicles have the potential to transform the way Americans travel through the creation of a safe, interoperable wireless communications network that includes cars, buses, trucks, trains, traffic signals, cell phones, and other devices. Like the Internet, which provides information connectivity, connected vehicle technology provides a starting point for transportation connectivity that will potentially enable countless applications and spawn new industries.

Connected vehicle applications provide connectivity:

• Among vehicles to enable crash prevention
• Between vehicles and the infrastructure to enable safety, mobility, and environmental benefits
• Among vehicles, infrastructure, and wireless devices to provide continuous real-time connectivity to all system users.

A connected vehicle network can vastly improve our nation’s transportation system in the areas of safety, mobility, and environment.

1.1 How Connected Vehicles Can Improve Mobility

Traffic congestion is an $87.2 billion annual drain on the U.S. economy, with 4.2 billion hours and 2.8 billion gallons of fuel spent sitting in traffic. Connected vehicles, using vehicle-to-infrastructure (V2I) capabilities and anonymous information from passengers’ wireless devices relayed through dedicated short-range communications (DSRC) and other wireless transmission media, has the potential to provide transportation agencies with dramatically improved real-time traffic, transit, and parking data, making it easier to manage transportation systems for maximum efficiency and minimum congestion. In addition, connected vehicles could enable travelers to change their route, time, and mode of travel, based on up-to-the-minute conditions, to avoid traffic jams.

1.2 How Connected Vehicles Can Improve the Environment

Tailpipe emissions from vehicles are the single largest human-made source of carbon dioxide, nitrogen oxides, and methane. Vehicles that are stationary, idling, and traveling in a stop-and-go pattern due to congestion emit more greenhouse gases (GHGs) than those traveling in free-flow conditions. Connected vehicle environmental applications, when implemented, will both generate and capture environmentally relevant real-time transportation data and use this data to create actionable information to support and facilitate green transportation choices. They will also assist system users and operators with green transportation alternatives or options, thus reducing the environmental impacts of each trip.

1.3 How Connected Vehicles Can Improve Safety

In 2009, there were 5.5 million crashes, almost 34,000 fatalities, and 2.2 million injuries on U.S. roads as the result of vehicle crashes. In 2010, the number of fatalities dropped by 3 percent but was still too high, accounting for 32,788 deaths according to the National Highway Safety Transportation Administration (NHTSA). Connected vehicle safety applications can increase situational awareness and reduce or eliminate crashes through vehicle-to-vehicle (V2V) and V2I data transmission. V2V and V2I applications enable vehicles to inform drivers of roadway hazards and dangerous situations that they can’t see through driver advisories, driver warnings, and vehicle and/or infrastructure controls.

According to a U.S. Department of Transportation (DOT) report, combined V2V and V2I systems potentially address about 81 percent of all-vehicle target crashes; 83 percent of all light-vehicle target crashes; and 72 percent of all heavy-truck target crashes annually. In the past, the U.S. DOT has focused on helping people survive crashes. Connected vehicle technology will change the paradigm by helping people avoid crashes.

2.0 2013 NHTSA Agency Decision and 2014 Heavy-Vehicle Decision

Because of the substantial impact that V2V and V2I technology could have on safety, NHTSA believes that this technology warrants consideration for possible regulatory action.  NHTSA has stated their intent to make an agency decision on V2V and V2I safety communications systems by 2013. NHTSA’s agency decision could include one of several options, such as:

• Future regulatory action
• Inclusion in the New Car Assessment Program (NCAP)
• Or, more research and development.

If justified, a regulatory approach would require manufacturers to include equipment to support V2V and V2I safety applications in new cars by a future date; the consumer information approach through NCAP would enable manufacturers to earn higher government safety ratings for vehicles that support the V2V and V2I safety applications. A similar milestone has been set in 2014 for a decision regarding V2V and V2I safety technology on heavy vehicles.

3.0 Recent Developments

3.1 Connected Vehicle Safety Pilot

Since 2002, the U.S. DOT has been engaged in research with automotive manufacturers on V2V crash avoidance systems that use very high-speed wireless communications and vehicle-positioning technology. In 2006, the U.S. DOT joined together with a partnership of automotive manufacturers, Crash Avoidance Metrics Partnership (CAMP), to develop and test prototype V2V safety applications. The overarching goal was to determine whether this technology would work better than existing vehicle-based safety systems, like adaptive cruise control, to address imminent crash scenarios.

Sound, robust data, such as that generated from CAMP’s research, is required for NHTSA to make an informed decision on the future of V2V and V2I safety communications systems. In addition to drawing information from previous tests and modeling, the Connected Vehicle Safety Pilot is a major source of robust data. This pilot is a real-world research test, conducted with CAMP (Ford, General Motors, Honda, Hyundai-Kai, , Volkswagen, Mercedes-Benz, and Toyota) and others to test V2V and V2I safety technologies, applications, and systems using everyday drivers. The effort will test performance, evaluate human factors and usability, observe policies and processes, and collect empirical data to present a more accurate, detailed understanding of the potential safety benefits of these technologies. This empirical data will be critical to supporting the 2013 NHTSA agency decision on vehicle communications for safety. The Safety Pilot program includes two critical test efforts—the Safety Pilot Driver Clinics and the Safety Pilot Model Deployment.

3.1.1 Safety Pilot Driver Clinics

Beginning in August 2011, Safety Pilot Driver Clinics will be conducted to assess user acceptance of the new V2V technologies using ordinary drivers in controlled roadway situations. The evaluations will explore driver reactions to safety applications using a variety of light-duty vehicles (cars) and under a variety of test conditions. Volunteers will participate in driver clinics in controlled environments such as test tracks and parking facilities. These clinics will be conducted at six sites geographically dispersed throughout the United States. Separate driver clinics will be conducted for trucks. 

The driver clinics are an important first step in identifying how drivers respond to new innovative wireless devices for safety. At each driver clinic, approximately 100 drivers will participate in testing the technologies to assess drivers’ response to in-vehicle alerts and warnings. Researchers in the vehicles will evaluate the driver experience and then follow with a series of questions once the test drives are complete. To ensure safety, drivers will be provided with advance training about the devices before they begin the tests. 

Six driver clinics will run from August 2011 to the spring of 2012. The first clinic will be held in Brooklyn, MI. The remaining clinics will be held in Minneapolis, MN; Orlando, FL; Blacksburg, VA; Dallas, TX; and San Francisco, CA.

Figure 1 - Locations of the Safety Pilot Driver Clinics

3.1.2 Safety Pilot Model Deployment

To continue the data collection under real-world conditions, a test site will be selected to host approximately 3,000 vehicles (cars, buses, and trucks) equipped with V2V devices. The goal is to test the effectiveness of the safety applications by creating a highly concentrated connected vehicle environment with vehicles “talking to each other.” The devices to be tested include embedded, aftermarket, and a “simple” beacon. All of these devices emit a basic safety message 10 times per second. When this data is further combined with the vehicle’s own data, it creates a highly accurate data set that is the foundation for cooperative, crash avoidance safety applications.

Using a mix of cars, trucks, and buses, the Safety Pilot Model Deployment will create test data sets for determining the technologies’ effectiveness at reducing crashes. These capabilities will also be extended to a limited set of V2I applications. Supported by a diverse team of industry, public agencies, and academia, the model deployment will run from the summer of 2012 to the summer of 2013.

The Safety Pilot will include some vehicles with integrated safety applications and others that use aftermarket devices (i.e., not built into the vehicle), which will communicate with surrounding vehicles using 5.9 Gigahertz (GHz) DSRC technology. Some of the safety applications to be tested include:

• Blind Spot Warning/Lane Change Warning, which warns drivers when they try to change lanes if there is a car in the blind spot or an overtaking vehicle.
• Forward Collision Warning, which alerts and then warns drivers if they fail to brake when a vehicle in their path is stopped or traveling slower.
• Electronic Emergency Brake Lights, which notifies drivers when a vehicle ahead that they can’t see is braking hard for some reason.
• Intersection Movement Assist, which warns the driver when it is not safe to enter an intersection—for example, when something is blocking a driver’s view of opposing traffic.
• Do Not Pass Warning, which warns drivers if they attempt to change lanes and pass when there is a vehicle in the opposing lane within the passing zone.
• Control Loss Warning, which warns the driver when another nearby vehicle has lost control.

3.2 Integrated Truck in Development

The Safety Pilot Driver Clinics will also include two trucks integrated with wireless crash warning devices. The driver clinics will obtain a cross-section of commercial vehicle drivers, recruited from local fleets and other means. The drivers will operate the vehicles in a safe, highly controlled, closed-course environment with a focus on collecting subjective driver acceptance data on integrated safety systems and driver vehicle interfaces.

In addition, at least one truck driver clinic will be held in conjunction with a trucking industry event or a similar fleet/driver-focused show.

3.3 Applications for the Environment: Real-Time Information Synthesis

Applications for the Environment: Real-Time Information Synthesis (AERIS) is the green research component of the ITS JPO’s multimodal ITS research initiative. The vision for AERIS research is to generate, capture, and analyze data to create actionable information that helps system users and operators make green transportation choices. For instance, informed travelers may decide to avoid congested routes; take alternate routes or public transit; or reschedule their trip—all of which can make their trip more fuel-efficient and eco-friendly. Data generated from connected vehicle systems can also provide operators with detailed, real-time information on vehicle location, speed, and other operating conditions. This information can be used to improve system operation. Onboard equipment may also advise vehicle owners on how to optimize the vehicle’s operation and maintenance for maximum fuel efficiency.

Through research, the AERIS program intends to assess how the suite of V2V and V2I connectivity and communications options and data may contribute to air quality improvements and reductions in GHGs and pollutants and to evaluate and quantify the magnitude of these improvements. The program will investigate a handful of applications (and groups of applications) to determine whether they provide significant environmental benefits.

3.4 Selected Dynamic Mobility Applications

Dynamic mobility applications capitalize on vehicle-infrastructure connectivity such as data from vehicle probes and other real-time data sources, using DSRC and other wireless communications methods. The vision for the U.S. DOT’s dynamic mobility applications research is to provide significant improvements to mobility and accessibility by introducing innovative methods for operating existing transportation systems based on the availability of new data sources and communications methods, and by creating opportunities for greater integration across modes (e.g., light vehicles, transit buses, and heavy commercial vehicles).

The Dynamic Mobility Applications program seeks to identify, develop, and deploy applications that leverage the full potential of connected vehicles, travelers, and infrastructure to enhance current operational practices and transform future surface transportation systems management. The following are the high-priority applications selected by the Mobility program for initial development in 2011.

• Arterial Applications
• Freeway Applications
• Regional (Information) Applications
• Corridor (Control) Applications.

3.5 Core Systems Concept of Operations Meetings

Safety, mobility, and environmental applications of the connected vehicle program are underpinned by a new architecture. This new architecture identifies a core system with essential functions that must be provided. The U.S. DOT’s connected vehicle program envisions the combination of applications, services, and systems necessary to provide safety, mobility, and environmental benefits through the exchange of data between mobile and fixed transportation users. It consists of the following:

• Applications that provide functionality to realize safety, mobility, and environmental benefits
• Communications that facilitate data exchange
• Core system that provides the functionality needed to enable data exchange between and among mobile and fixed transportation users.

The core system’s main mission is to enable safety, mobility, and environmental communications-based applications for both mobile and non-mobile users. The scope of the core system includes those enabling technologies and services that will in turn provide the foundation for applications. The system boundary for the core system is not defined in terms of devices or agencies or vendors but by the open, standardized interface specifications that govern the behavior of all interactions between users.

The core system supports a distributed, diverse set of applications. These applications use both wireless and wireline communications.

At the time of the connected vehicle program’s onset, the Federal Communications Commission (FCC) allocated 75 Megahertz of spectrum in the 5.9 GHz frequency range for the primary purpose of improving transportation safety. In addition to safety of life and public safety applications, the FCC also allowed private and non-safety applications to make use of the spectrum on a lower-priority basis. This allowed the connected vehicle program and associated research efforts to test the capabilities of 5.9 GHz DSRC for vehicular-based safety and mobility applications.

Since then, the decision to use 5.9 GHz communications technologies was refocused on safety applications. The systems engineering project includes consideration of other means of communication, while still maintaining 5.9 GHz DSRC for V2V and V2I safety applications because of its high availability and very low latency characteristics.

A critical factor driving the conceptual view of the core system and the entire connected vehicle environment is the level of trustworthiness between communicating parties. A complicating factor is the need to maintain the privacy of participants, chiefly but not necessarily exclusively through anonymous communication. The core system is planning anonymity into the trusted exchange of data and balancing privacy against security and safety.

While the core system is being planned for anonymity, it is also providing a foundation from which to leverage alternative communications methods for non-safety applications. These alternatives are typically available on the market today; however, the levels of anonymity and privacy inherent to these systems are typically governed by agreements between communication providers and consumers. So, while privacy is not compromised for an individual, what happens between that individual and their communication provider (e.g., 3G service provider) very well may compromise privacy. Similarly, some application providers may require personal information in order to function, requiring the user to opt-in to use that application.

3.6 Harmonization of International Standards and Harmonization of Selected Applications

Similarly, ITS Standards and Architecture Harmonization is a key research program of the ITS JPO. The program teams with standards development organizations and public agencies to accelerate the development of open, non-proprietary communications interface standards to support ITS application development and deployment. These standards define how ITS systems and components interconnect and exchange information to deliver ITS services within a multimodal transportation network. The consistent and widespread use of ITS standards will permit data and information sharing among public agencies and private organizations, fostering an environment of information sharing and interoperability. Currently, nearly 100 standards have been developed under this program.

Through the ITS Standards and Architecture Harmonization program, the U.S. DOT participates in international standards harmonization activities focusing on standards needed to provide connectivity among vehicles and between vehicles and infrastructure.

It is critical to reduce barriers to standardization and achieve a broad agreement on harmonization that can benefit both the public and the motor vehicle industry. To that end, the U.S. DOT has established a Joint Declaration of Intent on Research Cooperation in Cooperative Systems with the European Union. The purpose of the agreement is to encourage international cooperation on information and communication technology research, as applied to transportation. The U.S. DOT and the European Commission Information Society and Media Directorate have agreed on a harmonization action plan, which will be addressed by coordinated or joint research. In particular, the parties intend to make efforts to preclude the development and adoption of redundant standards and to support and accelerate the deployment and adoption of cooperative systems.

4.0 Policy Implications for Connected Vehicles

The ITS JPO Policy and Institutional Issues program was established to identify, research, analyze, and present policy options to enable successful connected vehicle implementation. Its mission is to identify critical issues that may hinder or present challenges to successful implementation of ITS technologies.

Of particular interest and focus to the ITS JPO’s policy program are the societal and institutional frameworks that will enable U.S. DOT connected vehicle research to transition to implementation. Privacy and security, along with the variety of institutional issues that may exist, are of paramount importance. The U.S. DOT actively works to engage a wide range of stakeholders to help guide policy research such that it is based on sound, real-world application of the new technologies.

Implementation can only be successful if complex policy issues are addressed side by side with technical issues. These issues are not new; the U.S. DOT has facilitated meetings and discussions between the automotive industry, state DOTs, and others for many years. Today, work is intensifying to address issues such as:

• Infrastructure options for security networks
• Governance of security certificates for safety
• Privacy provisions, which have been a key part of the program since inception
• Business modeling to ensure sustainable funding for implementation, operations, and maintenance.

4.1 Preventing Distracted Driving, a Top U.S. DOT Priority

Minimizing driver distraction is a major factor in the design of all connected vehicle applications, whether the application is for safety, mobility, or the environment. According to the U.S. DOT, nearly 5,500 people in the United States were killed and almost half a million were injured in accidents related to distracted driving in 2009. Eighteen percent of those fatal accidents involved the use of a cell phone.

The U.S. DOT is leading the effort to put an end to distracted driving. The U.S. DOT’s ITS Strategic Research Plan includes a research program to study human factors issues specific to connected vehicle technology. This program will develop interface guidelines aimed at reducing any potential risks and focusing the driver’s attention on the roadway when a collision is imminent.  

5.0 Looking Ahead

Safety is the number one priority of the U.S. DOT. Emerging, state-of-the-art technologies and systems, like those being advanced by the ITS program, will help usher in an era of unprecedented road and highway safety. What once was considered science fiction—vehicles that communicate and help drivers make life-saving decisions—may be a reality in the coming decades. 

Today, when we get behind the wheel, we expect our vehicles to be built to help us survive that terrifying moment when a crash happens. Seatbelts and airbags are ubiquitous in our vehicles’ fleets, and have been a critical factor in reducing roadway deaths to record lows. The U.S. DOT anticipates that one day, collision warning systems and other pioneering connected vehicle applications will be an expected feature and a part of our daily driving experience—as ordinary as buckling up. 

The potential for V2V and V2I communication systems to revolutionize roadway safety is real. Additional challenges lie in testing new applications and deploying effective technology into vehicle fleets and communities as soon as feasible.   

The past 50 years have been about surviving vehicle crashes; the next 50 will be about preventing them.