Foothill Gold Line train passes through Highland Avenue intersectionnear the Duarte Station Monday, February 9, 2015. Train testing has begun on the 11.5-mile Foothill Gold Line between Pasadena and Azusa, from Monday, through Summer 2015. Train testing is currently taking place in the cities of Duarte and Irwindale, and will expand to Pasadena, Arcadia, Monrovia and Azusa over the next several months.Systems integration testing is when the train is moving and they're looking to see how it works together. Train will be running between Myrtle Avenue and Irwindale, back and at 15 mph.T(Photo by Walt Mancini/Pasadena Star-News)