sentences:  Three major projects were ongoing, the US Standard Light Rail Vehicle (LRV); the State of the Art Car (SOAC), a prototype subway car that included all of the most modern features; and the Transbus urban mass transit bus.Many of these were being worked on with Boeing Vertol, who showed both the prototype SOAC car and the design of their LRV.Similar vehicles were also being developed by other aviation firms, especially Rohr.