Crash Data Analyses for Vehicle-To-Infrastructure Communications for Safety Applications

Chapter 3. Overview of Current V2I Application Areas

The V2I application areas currently being considered by the FHWA Safety Program are characterized as intersection applications, speed applications, applications for vulnerable road users, and others.

Intersection applications are intended to prevent crashes at intersections and include the following:

• Drivers running red lights.
• Drivers running stop signs.
• Driver gap assist at signalized intersections.
• Driver gap assist at stop-controlled intersections.

Speed applications are intended to target crashes involving one or more vehicles when speeding contributed to the crash. These applications include the following:

• Curve speed warning.
• School zone speed warning.
• Work zone warning for reduced speed in work zones.
• Spot treatment/weather conditions.
• Speed zone warning.

Vulnerable road user applications are intended to target crashes involving users, such as pedestrians or vehicles, in vulnerable situations. These applications include the following:

• Work zone alerts.
• Infrastructure pedestrian detection.
• Priority assignment for emergency vehicle preemption.
• At-grade rail crossing.
• Bridge clearance warning.

Other applications that do not fit into the aforementioned categories include the following:

• Secondary accident warning.
• Lane departure warning.

Table 8 summarizes estimates that could be derived from a NASS GES-based analysis of the number of annual crashes that could be targeted by the current application areas. Note that it does not include data for several current application areas including school zone warning, emergency vehicle preemption priority, bridge clearance warning, and secondary accident warnings. The NASS GES system is based on a sample of police-reported crashes and is limited to the variables collected by the police. This restricts the ability to identify some of the circumstances of the crash that would be needed for these four applications. For example, the secondary accident warning application is intended to target crashes that occur, at least in part, following another crash (e.g., a rear-end crash in congestion that was caused by an earlier crash). This scenario is not specifically recorded by the police, and these crashes cannot be identified in NASS GES.

Table 8. Summary of annual estimated targeted crashes based on current applications.

N/A = Not applicable.

There is some overlap in the crashes targeted by the application areas, and some of these crashes can be targeted by more than one application. For example, some crashes can be targeted by the curve speed warning and the spot treatment/weather conditions applications.

The following sections provide information on the estimated annual crashes that may be targeted by each application area based on the analyses of NASS GES data. Crashes are described as targeted crashes or unaddressed crashes with respect to V2I application areas. Targeted crashes are crashes that could potentially be eliminated through the deployment of a specific V2I application or set of applications (i.e., after determining the potential benefit of an application area assuming 100 percent effectiveness and 100 percent deployment). The actual number of crashes addressed will depend on the effectiveness of the application and the extent to which they are deployed. Unaddressed crashes are those that would not be eliminated even if a V2I application or set of applications were 100 percent effective and fully deployed. Unaddressed crashes might be covered through the development of new applications or by other technologies.