Connected Vehicle Applications
Vehicle-to-Infrastructure (V2I) Communications for Safety

Research Overview

Vehicle-to-infrastructure communications for safety is the wireless exchange of critical safety and operational data between vehicles and highway infrastructure, intended primarily to avoid or mitigate motor vehicle crashes but also to enabe a wide range of other safety, mobility, and environmental benefits.  V2I communications apply to all vehicle types and all roads, and transform infrastructure equipment1 into “smart infrastructure” through the incorporation of algorithms that use data exchanged between vehicles and infrastructure elements to perform calculations that recognize high-risk situations in advance, resulting in driver alerts and warnings through specific countermeasures.  One particularly important advance is the ability for traffic signal systems to communicate the signal phase and timing (SPAT) information to the vehicle in support of delivering active safety advisories and warnings to drivers.  Early implementation of the SPAT application can enable near-term benefits from V2I communications in the form of reduced crashes, which in turn demonstrate benefits that can help accelerate deployment. 

The vision of V2I Communications is that a minimum level of infrastructure will be deployed to provide the maximum level of safety and mobility benefits for highway safety and operational efficiency nationwide.  Importantly, V2I communications have the potential to resolve an additional 12 percent of crash types not addressed under V2V communications.  V2I Communications for Safetyis a key technology in the USDOT's Connected Vehicles Program, and is complimented by the V2V communications research.  While the primary goal is safety, V2I communications are also significant in improving mobility and environment by reducing delays and congestion caused by crashes, enabling wireless roadside inspections, or helping commercial vehicle drivers identify safe areas for parking.

The objectives of the V2I Communiications for Safety research program are fourfold: (1) building from the research results under the prior Vehicle Infrastructure Integration (VII) program and VII proof-of-concept test, to complete the development and testing of the V2I communications technologies, advanced applications, and standards for national interoperability—in particular, the SPAT capability; (2) to develop a rigorous estimation of safety benefits and develop a regulatory/policy guidance versus market position in support of deployment, (3) to provide tools and information that support infrastructure deployments nationwide, and (4) and to ensure appropriate strategies are implemented for privacy, security, system certification and accessibility, scalability, governance structures, public acceptance, and a sustainable marketplace that can effectively propel deployment.

Because of the great variety of vehicle and infrastructure safety systems now installed and planned for the future, the focus on consistent, widely applicable standards and protocols is critical.  Additionally, the research will concentrate on the key FHWA and FMCSA application areas of interest, including intersection safety, run-off-road prevention, speed management, and commercial vehicle enforcement and operations. 

Research Questions

The following research questions will be answered by the V2I Communications for Safety Program

  • What safety applications are effective and have validated benefits?
  • What minimum infrastructure is needed for maximum benefit? (Initial deployment)
  • Can SPAT and mapping information be transmitted over a wireless network via a universal architecture?
  • What degree of market penetration is required for effectiveness?
  • Are there unique applications for specialty vehicles (transit bus, commercial vehicles, light rail, etc)?

Research Approach


V2I Communications for Safety will provide cooperative and communications-based applications designed to assist vehicle operators avoid vehicular crashes.  The technologies under investigation will provide a graduated spectrum of safety interfaces from in-vehicle information and advisories to in-vehicle driver warnings of imminent crash scenarios.  These interfaces will be based on open standards for all applications.  Dedicated Short Range Communications (DSRC) will be used for time critical safety applications.

The V2I communications program is designed to enable the exchange of data over a wireless network which enables each vehicle on-board equipment (OBE), device (e.g. handheld cellular devices, aftermarket portable GPS devices), or roadside equipment (RSE) to perform calculations and issue driver advisories and warnings to avoid or mitigate crashes through specific advanced safety applications.  This plan will pursue activities that will validate, assess, and estimate benefits for high value applications and enable national interoperability for the transmission of safety related information exchange (e.g., signal phase and timing data) between roadside equipment (RSE) and/or nearby vehicles. For the commercial vehicle enforcement applications this plan establishes research and demonstration activities to support enforcement regulations and real-time parking information in a wireless environment.

The six (6) V2I Communications for Safety program tracks represent the research work necessary to enable a deployable connected vehicle system, but it does not represent actual implementation of a deployed solution. 

Through collaborative research, participation in standards development, and other research efforts, the ITS Program will engage the appropriate parties in a multi-track program that addresses the breadth of technical and non-technical V2I research needs. 

Program Tracks

Track 1 – Application Analysis
The key objective of this track is to determine the high value safety applications that will be initially addressed for V2I deployment.  This track will analyze crash data to identify, verify, and prioritize applications that should be pursued as part of the V2I research.  The following application areas will be the initial focus of the crash analysis:

  • Intersection safety
  • Run-off-road
  • Speed management
  • Commercial/transit vehicle enforcement and operations for safety

Track 2 – Prototype Applications
The key objective of Track 2 is to develop and validate prototypes of high value cooperative safety applications that will be field operationally tested in Track 4.  Requirements from each application related to positioning, mapping, security, and communications will be used as input to Track 3 - Infrastructure Prototyping Efforts.  Prototyped safety applications will undergo integration and testing as part of Track 3.

Track 3 – Infrastructure Communications/Interoperability
The key objective of this track is to provide the critical technological underpinnings that allow safety applications to work at locations throughout the United States of America.  Interoperability is critical to the deployment of V2I safety systems and will facilitate national availability and consistency across all connected vehicle applications. 

Track 4 –Benefits Assessment
The key objective of this track is to quantify safety benefits that may be realized by deployment of V2I applications.  The results of testing will be used to support deployment decisions, policies, and rulemaking. 

Track 5 – Deployment Planning
The key objectives of this track are to:

  • Identify infrastructure needed to support initial deployment
  • Define application effectiveness vs. market penetration for initial set of applications
  • Conduct study and assessment on leveraging aftermarket and retrofit opportunities to provide benefits more rapidly.
  • Provide tools and guidelines for practitioners to deploy and maintain V2I systems.

Track 6 – Policy
The key objective of this track is to develop policy requirements that may be unique to V2I Communications for Safety applications.  The connected vehicle policy roadmap will identify the overall policy and governance issues and the V2I team will give input to the policy team as issues are identified.  No funded activities are planned at this time for the V2I program that concern policy related issues


Research Contacts

To learn more about this research, contact:

Brian Cronin
Team Lead, Research
ITS Joint Program Office
Research and Innovative Technology Administration
(202) 366-8841

1. Includes highway equipment, systems, and structures (other than vehicles) such as roadside signals (stoplights, warnings, variable message signs, etc.), traffic management centers, weather information systems, or signal phase and timing systems, among others. 


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