Starting in the 20th century, the technological requirements needed to build large crossings across the river were met. This was especially important by New York City, as the river is fairly wide at that point. In 1927, the Holland Tunnel opened between New Jersey and Lower Manhattan. The tunnel was the longest underwater tunnel in the world at the time, and used an advanced system to ventilate the tunnels and prevent the build-up of carbon monoxide. The original upper level of the George Washington Bridge and the first tube of the Lincoln Tunnel followed in the 1930s. Both crossings were later expanded to accommodate extra traffic: the Lincoln Tunnel in the 1940s and 1950s, and the George Washington Bridge in the 1960s. In 1955, the original Tappan Zee Bridge was built over one of the widest parts of the river, from Tarrytown to Nyack.