To address overcrowding, in 1909, the New York Public Service Commission proposed lengthening platforms at stations along the original IRT subway. As part of a modification to the IRT's construction contracts, made on January 18, 1910, the company was to lengthen station platforms to accommodate ten-car express and six-car local trains. In addition to $1.5 million (equivalent to $ million in ) spent on platform lengthening, $500,000 () was spent on building additional entrances and exits. It was anticipated that these improvements would increase capacity by 25 percent. The northbound platform at the 137th Street station was extended to the south, while the southbound platform was not lengthened. On January 24, 1911, ten-car express trains began running on the West Side Line. Subsequently, the station could accommodate six-car local trains, but ten-car trains could not open some of their doors.