Simulation Study Found 64.8 Percent More Lateral Space Provided for Passing Emergency Vehicles by Drivers Equipped with a Warning System of Emergency Vehicles.
Swedish Study Evaluated the Safety Impacts of Using Emergency Vehicle Approaching Messages Using Driver Simulator with 90 Participants.
Nationwide, Sweden
In-Car Warnings of Emergency Vehicles Approaching: Effects on Car Drivers' Propensity to Give Way
Summary Information
Emergency driving, involving authorized vehicles responding to urgent situations, carries heightened accident risks due to high speeds, complex driving tasks, and the need for rapid navigation through traffic. This study employed Emergency Vehicle Approaching (EVA) messages, which are hyper-local alerts delivered via a Radio Data System (RDS) over FM radio, targeting only those drivers directly ahead of the emergency vehicle. Unlike broad radio announcements prone to false alarms, EVA messages provide timely, specific warnings intended to enhance situational awareness, improve compliance, and support safer, more efficient emergency transport. The study used a simulation approach to evaluate the effectiveness of EVA messaging in enhancing drivers’ propensity to yield under various conditions and levels of driving experience.
METHODOLOGY
Two driving simulator experiments with 90 participants examined how driver experience and ambulance visibility affected responses to emergency vehicles: 1) drivers were passed three times in easy-to-detect conditions, comparing two EVA message versions to no message, and 2) with harder detection conditions, drivers were passed once and either received an EVA message or no message. The study employed a between-groups design, randomly assigning participants to either the EVA message or the no-message condition. Key dependent variables included the distance at which drivers gave way, their lateral position when overtaken, and their speed at the moment of overtaking, enabling assessment of how EVA messaging influenced yielding behavior under more challenging detection conditions.
FINDINGS
- Participants who received EVA messages provided 64.8 percent more lateral space for emergency vehicles to pass compared to those who did not.
- The speed at the time of the emergency vehicle's overtaking was 56.6 percent slower for participants who received EVA messages.
- The distance at which drivers gave way to the emergency vehicle was 2.64 times further for participants who received EVA messages.
