The 155th Street Viaduct opened on October 10, 1893. The over-water span opened "without any particular ceremony" a year and a half later, on May 1, 1895. The viaduct cost $739,000 (about $ million in ), while the over-water span cost $1.3 million (equal to $ million in ); however, the total cost of the over-water span including land acquisition was $1.774 million (about $ million in ). The new bridge was also called the Central Bridge, and though a plaque bearing this name still can be seen on the swing span, the name never stuck. The old "Macombs Dam" name remained in popular use, and the bridge was officially renamed with its original moniker in 1902. The 155th Street Viaduct and over-water span were formerly operated by two different entities. The over-water span was erected by the New York City Department of Parks and Recreation before being transferred to the Bridge Department in 1898, while the 155th Street Viaduct was erected by the Department of Public Works and was transferred to the Manhattan borough president's office in 1898. A trolley franchise was awarded to the Union Railroad Company in 1903, providing Bronx residents with a direct connection to the Eighth Avenue trolley. The first trolley traveled over the Macombs Dam Bridge in 1904. Due to the increasing prevalence of trolleys and automobiles, there was a decrease in horse-drawn carriages that used the bridge. Also in 1904, the steam engine that powered the movable over-water span was replaced with a electric motor, which itself was replaced with a motor in 1917. The New York City Department of Plant and Structures assumed control of the over-water span in 1916, and five years later it also had jurisdiction of the 155th Street Viaduct. In 1920, while Yankee Stadium was under construction, ramps were built on the Bronx side of the Macombs Dam Bridge, leading to 161st Street. As part of this project, the staircase on the northern facade of the Bronx abutment was demolished, and a corresponding stair on the southern facade was built. On the Manhattan side, a rebuilt approach from Seventh Avenue and 151st Street to the bridge, as well as a rebuilt triangular plaza between Seventh Avenue and Macombs Dam Road, was opened in 1931. The approach was built on land donated by John D. Rockefeller Jr. The new approach, designed by Andrew J. Thomas, entailed rebuilding the formerly-straight Macombs Dam Road approach to a "flared polygonal" route, which required extending the masonry abutment there.