In-vehicle Dynamic Curve Speed Warnings At High Risk Rural Curves

Project summary:

Lane departure crashes at horizontal curves represent a significant portion of fatal crashes on rural Minnesota roads. The most common method for warning drivers about hazardous horizontal curves is with infrastructure-based systems ranging from standard curve warning signs to sensor-triggered dynamic warning displays. Although these methods are effective, their cost can be difficult to justify, especially for rural roads with low traffic volumes where hazardous curves are most common.

One solution that seeks to avoid costly infrastructure-based methods is to use in-vehicle technology to display dynamic curve speed warnings to the driver. Such a system would consist of a device located in the vehicle that is capable of providing a visual and auditory warning when approaching a hazardous curve at an unsafe speed. This would serve to notify the driver of both the curve's presence and that they are exceeding the advisory curve speed. This requires a database storing both the location of hazardous curves and their associated advisory speed.

This project sought to determine the efficacy of in-vehicle dynamic curve speed warnings as deployed on a smartphone app. First, a warning method was selected that is effective but also does not distract the driver from navigating the curve. This was incorporated into an app capable of displaying the warning to drivers based on their speed and distance to the curve. The app was evaluated using drivers on real roads in a pilot study. Data was collected to determine how well the system affects change in the drivers' behavior.

• OST-R summary report for this project (PDF)