The U.S. Standard Light Rail Vehicle was designed by Boeing Vertol Company to replace the aging streetcars in several U.S. cities, and to provide an efficient vehicle for new light rail transit systems. The paper briefly describes the technical and design features of the LRV. It also describes the test program that was part of the development effort. The paper discusses test results achieved in testing and compares them with specification requirements. The paper discusses problems encountered during the test and development program. Finally the paper describes the initial introduction of the LRV into revenue service in Boston.