The Effect of City Bus Maneuvers on Wheelchair Movement

A state-of-the-art four-point tiedown system, a prototype automatic docking system, and a prototype rear-facing wheelchair passenger station (RF-WPS) were installed in a large accessible transit vehicle (LATV). A manual wheelchair, powered wheelchair, and a three-wheeled scooter were used to test the securement performance of each wheelchair securement system during LATV normal driving, hard braking, and rapid turning maneuvers. All test wheelchairs were loaded with an ISO 7176 Part 11 compliant loader gage representing the weight of an average male wheelchair occupant. A tri-axial accelerometer measured vehicle acceleration during driving maneuvers, and a low-tech movement tracking system measured wheelchair movement during driving maneuvers. Results show that each wheelchair securement system limited wheelchair displacement to less than the 51-mm Americans with Disabilities Act (ADA) displacement limitation, and none of the securement systems showed visible signs of failure. Accelerations during LATV normal driving, hard braking, and rapid turning did not exceed 0.76 g