This report proposes cost-effective design guidelines to increase ride comfort, safety, and transit bus utility levels by specifying the visual cue requirements that will allow elderly riders to maintain a maximum sense of balance and spatial orientation. Human subjects were used to obtain both objective and subjective data. Objective date included the subjects' gripping force exerted on the stanchions. Subjective data obtained through jury evaluations provided information on perceived ease of balance maintenance. The jurors, who ranged in age from 55 to 75 years old, were given rides on an actual transit bus route of medium roughness. Each juror took six rides with different visual surroundings. A second phase of the project used the Federal Highway Administration's DYNTRAC to include only vertical excitation of the vehicle. It was shown that the longitudinal excitations were mainly responsible for the difficulty with postural stability on a moving bus. The results suggest that the use of vertical geometric patterns is a viable intervention strategy to optimize visual orientation and postural stability of subjects (i.e., reduce the incidence of falling) on a moving transit bus.
Abstract