It carried two tracks of the New York and Putnam Railroad, and later the 9th Avenue elevated line of the Interborough Rapid Transit Company (IRT), as well as two pedestrian walkways outside the superstructure.

[2] The Putnam Bridge was built by the New York City & Northern Railroad, a predecessor of the NY&P, and operated by its subsidiary, the West Side & Yonkers Railway (not to be confused with the West Side & Yonkers Patent Railway, the original operator of the 9th Avenue line).

Through service over this new line to the 167th Street station was inaugurated July 1 of that year, and extended to the northern terminus at Woodlawn by January 2, 1919.

However, the New York Giants baseball team was moved from the Polo Grounds to San Francisco after the 1957 season, and the Putnam Division ceased running passenger service on May 29, 1958.

These two events reduced ridership to the extent that it was no longer economically feasible to continue running the shuttle, and it was discontinued August 31, 1958.