Holland Tunnel

The Holland Tunnel is a vehicular tunnel under the Hudson River that connects Hudson Square in New York City to Jersey City, New Jersey. It carries Interstate 78 and is operated by the Port Authority of New York and New Jersey. The tunnel was designed by Clifford Milburn Holland and Ole Singstad, and it opened in 1927 as the longest continuous underwater tunnel for vehicular traffic in the world. It features two parallel tubes, each with a 29.5-foot diameter and 20-foot roadway, and is ventilated mechanically. The tunnel was designated a National Historic Civil and Mechanical Engineering Landmark in 1982 and a National Historic Landmark in 1993. It has a maximum grade of 4.06% and a vertical clearance of 12 feet 6 inches, and is limited to vehicles with a width of 8 feet or less.learn more on wikipedia