Date of Award


Degree Name

Master of Science in Engineering


Mechanical and Aerospace Engineering

First Advisor

Dr. James W. Kamman

Second Advisor

Dr. Rameshwar P. Sharma

Third Advisor

Dr. Kapseong Ro

Access Setting

Masters Thesis-Campus Only


The increased popularity of hybrid electric vehicles has created a growing concern for the safety of blind and visually impaired pedestrians. Accident data published by the National Highway Traffic Safety Administration demonstrates a higher incident rate involving hybrid electrics vehicles compared to internal combustion engine vehicles during slow speed (15 kph or less) movement. The lower sound output of hybrid electric vehicles, compared to internal combustion engine vehicles, has been reported as the reason for the high incident rates. Previous studies have focused on the overall sound pressure level of vehicles related to the ability of blind pedestrians to safely cross streets. Under more controlled conditions and lower ambient sound pressure levels than was achievable in previous research, measurements were made comparing the detections of hybrid electric vehicles, internal combustion engine vehicles, and hybrid electric vehicles with added sounds. Vehicle detection tasks confirmed that when moving at slow speeds, a hybrid electric vehicle is detected, by blind pedestrians, at a closer distance and smaller safety margin when compared to traditional internal combustion vehicles. Adding additional sound to a hybrid electric vehicle resulted in detections made at a greater distance.

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