The Holland Tunnel connecting Manhattan to Jersey City opens at midnight to thousands of cars waiting to drive through the world’s longest underwater vehicular tunnel at the time. Earlier that day, some 20,000 pedestrians walked the entire 9,250-foot length.
The Holland Tunnel is named for Clifford Milburn Holland, its initial chief engineer, who died suddenly in 1924 prior to its opening. It was the world's first mechanically ventilated tunnel, with a ventilation system designed by Ole Singstad, who oversaw the tunnel's completion. The tubes are made of cast-iron rings covered by concrete and measuring 29.5 feet (9.0 m) in diameter, running parallel under the river. Each tube fits two lanes and has 12 feet 6 inches (3.81 m) of vertical clearance. At the western end of the tunnel, the westbound tube exits onto 14th Street, while the eastbound tube is accessed from Boyle Plaza on 12th Street. At the eastern end, the eastbound tube exits onto the Holland Tunnel Rotary (occupying the site of the former St. John's Park Terminal), while the westbound tube is accessed from Freeman Plaza.
Plans for a fixed vehicular crossing over the Hudson River were first drawn up in 1906. Disagreements prolonged the planning process until 1919, when a tunnel under the river was approved in lieu of a bridge. Construction of the Holland Tunnel started in 1920, and it opened in 1927. At the time of its opening, it was the longest continuous underwater tunnel for vehicular traffic in the world. There were plans to connect the tunnel to highways on both ends, but the highway on the New York side, the Lower Manhattan Expressway, was never completed. Tolls were collected in both directions until 1970, when tolls for westbound traffic were abolished. The tunnel was refurbished in the 1980s and the 2020s.
