The Holland Tunnel is a highway tunnel under the Hudson River connecting the island of Manhattan in New York City with Jersey City, New Jersey at Interstate 78 on the mainland.

          The tunnel was originally known as the Hudson River Vehicular Tunnel or the Canal Street Tunnel and is one of two highway tunnels under the Hudson River (the Lincoln Tunnel is the other).

The tunnel consists of a pair of tubes, each providing two lanes in a twenty foot roadway width. The north tube is 8,558 ft (2,608 m) from end to end, while the south tube is slightly shorter at 8,371 ft (2,551 m). Both tubes are situated in the bedrock beneath the river, with the lowest point of the roadway approximately 93 feet (28 m) below mean high water. A nine-lane toll plaza equipped with E-ZPass is located on the New Jersey side of the tunnel. As of 2003, the charge for passage from New Jersey to New York is $6 for cars and $5 for motorcycles (there is no toll in the opposite direction). According to the Port Authority of New York and New Jersey, which controls the tunnel, traffic for 2002 totalled 15,764,000 vehicles, 33,926,000 vehicles in 2004, and 33,964,000 vehicles in 2005. The Tunnel was added to the National Register of Historic Places in 1993 (Structure #93001619).

Accidents and terrorism

In 1949, a fire aboard a chemical truck caused enormous damage to the south tube of the tunnel. Although nobody was killed, the fire resulted in 66 injuries and nearly $600,000 worth of damage to the structure. As a result, the Port Authority adopted a strict series of rules on the transportation of hazardous materials within the tunnel.

                Following the September 11, 2001, terrorist attacks on the World Trade Center, the tunnel remained closed to all but emergency traffic for nearly a month. When it reopened, strict new regulations were enacted banning single-occupant vehicles and trucks from entering the tunnel. It wasn't until November 17, 2003, that the single occupancy vehicle restrictions were lifted. Tractor trailers and trucks in classes four, five, and six (four, five, and six-axle trucks) are still prohibited from using the tunnel. Cell phone service was turned off after the 2005 terrorist bombings in London, but reinstated a few days later.

               On July 7, 2006, a plot to detonate explosives in the tunnels of the Port Authority Trans-Hudson (initially said to be a plot to bomb the Holland Tunnel) was uncovered by the Federal Bureau of Investigation. The plot included the detonation of a bomb that could significantly destroy and flood the tunnels including all the occupants and vehicles in the tunnel at the time of the explosion. The terror planners believed that the explosions would cause Lower Manhattan to flood due to riverwater surging up the tunnel remains after the blast. Officials say that this plan was unsound due to the strength of the tunnels, and that it would require a large amount of explosives to explode. Since semi-trailer trucks are currently not allowed to pass through the Holland Tunnel (and the PATH tubes are for trains), it would be very difficult to get sufficient explosives into the tunnel to accomplish the plan. If the tunnel were to explode and allow water from the Hudson River to flood the Holland Tunnel, Lower Manhattan would be spared since the area is 2-10 feet (1-3 meters) above sea level. Three of the eight planners have been arrested, based in six different countries[2]. This threat may have taken some inspiration from the 1996 movie Daylight, which may have, in turn, been inspired by the 1949 Holland Tunnel fire.