The first problem would remain unsolved despite a proposal for a tunnel in North Philadelphia that was to run to the Broad Street Station area and then emerge above ground to meet the lines coming out of the station. The other problem began to be alleviated with electrification of the rail lines, starting with the Paoli service to the railroad's "Main Line", starting on September 11, 1915. In 1918 service to Chestnut Hill (today's Chestnut Hill West) was opened, and the two busiest commuter services were dealt with.