Far too many people were being hit by trains - since the line to Morrellville was street level. So it was decided to construct a series of underpasses to help keep accidents down by elevating the tracks. There were two major problems - first off, the trolleys couldn't go up Fairfield Avenue before this and secondly - people were gettting hit by passing trains since they had to cross the train tracks to take another trolley to the rest of Morrellville.
Wish I knew who that kid was on the right hand side. Mostly likely someone from either Pennsylvania or Virginia Avenue.