Alden staRRcar, 1966. A proposal by William Alden for a dual-mode transit system whereby electrically powered vehicles could be driven independently before joining up with a tracked network which would take over both powering and navigating the unit thus making the vehicle autonomous for longer journeys. The idea was developed by Boeing Vertol into a much larger tracked vehicle for 20 people that became the Morgantown Personal Rapid Transit system which first opened for service in 1975, and with the exception of a closure for expansion, has remained in service ever since