Driver warning systems are a tool in the pursuit of safer urban areas. Older drivers my especially benefit as they are over-represented in urban crashes. The aim of this driving simulator study was to determine whether a heads-up warning showing a stop sign warning (SW) or caution sign warning (CW) 2.5 seconds prior to the anticipated crash would have a better effect on the driving performance of older drivers (compared to the control group) in scenarios of different criticalities. Thirty-six older drivers (average age of 71.9, average 49.7 years driving experience) were divided into three groups: SW, CW, and a control. Each participant drove through four scenarios.
- Pedestrian 1 scenario: while turning a pedestrian crosses the vehicle’s path.
- Pedestrian 2 scenario: a pedestrian, obscured by parking cars, suddenly crosses the vehicle path.
- Vehicle scenario: lead vehicle comes to a sudden stop.
- Obstacle scenario: driver is confronted with a hay bale hidden behind a hill.
In each scenario the vehicle driven by the participant travels through a simulated urban road and has to make a turn when indicated by a voice output and an arrow in the speedometer. After the test drive, each subject was asked about the criticality and surprise of each scenario. Driving data was logged by the simulation software. Participant’s subjective data was converted to a rating on a scale from 1 to 15.
Integrate stop and caution warning signage into heads-up displays to help older drivers brake sooner for potential hazards.
- Study participants reacted fastest and most aggressively (based on pressure applied to the brake pedal) to the stop sign warnings in all scenarios. This emphasizes the importance of understanding what behaviors a warning might trigger.
- In scenarios where the driver has to react immediately, the stop sign warning is best suited. However, the caution sign warning is likely better suited for scenarios where sudden and firm braking is not needed.