We describe an algorithm based on motion-planning techniques to determine the existence of an accessible route through a facility for a wheeled mobility device. The algorithm is based on LaValle's work on rapidly exploring random trees and is enhanced to take into consideration the particularities of the accessible route domain. Specifically, the algorithm is designed to allow performance-based analysis and evaluation of a facility. Furthermore, the parameters of a wheeled mobility device can be varied without recompilation, thus allowing standards writers, facility designers, and wheeled mobility device manufacturers to vary them accordingly. The algorithm has been implemented in a computer tool that works within a computer-aided design and drafting environment. (Contains 16 figures.)