GETTING ACTIVE WITH PASSIVE CROSSINGS: INVESTIGATING THE EFFICACY OF IN-VEHICLE AUDITORY ALERTS FOR RAIL ROAD CROSSINGS

Train-vehicle collisions at highway-rail grade crossings continue to be a major issue in the US and across the world. Installing additional hardware at individual crossings is expensive, time consuming, and potentially ineffective. To prevent recent trends in safety improvement from plateauing, experts are turning towards novel warning devices that can be applied to all crossings with minimal cost. In-vehicle auditory alerts (IVAAs) could potentially remedy many of the human factor issues related to crossing safety in a cost effective manner. This thesis presents a series of experiments designing and testing an IVAA system for grade level railroad (RR) crossings. Study 1 collected subjective data on a pool of potential in-vehicle auditory alerts from 31 undergraduate participants. The type of IVAAs was varied along a number of dimensions (pitch, repetition, wave shape, wording, voice, etc.). Results from study 1 were used to design a prototype IVAA crossing notification system. A pilot study was conducted to calibrate the simulated driving scenario featuring multiple RR crossings and a compliance behavior coding procedure. Compliance behavior was operationalized as an amount of visual scanning and pedal depression. Study 2 recruited 20 undergraduate participants to drive in a medium fidelity driving simulator featuring four types of RR crossings with and without IVAAs. Results suggest that IVAAs not only inform and remind drivers of how to comply at RR crossings, but also have a lasting effect on driver behavior after the IVAA is no longer presented. Compliance scores were highest among novel RR crossing visual warnings such as crossbucks featuring STOP or YIELD signs. Compliance was lowest for crossbucks alone and active gates in the off position. IVAAs had the largest impact on compliance scores at crossbucks and gates. The discussion includes implications for designing IVAA systems for RR crossings, and the potential implementation of prototype systems as a smartphone application