The Port Authority manages the bulk of the bi-state transportation system between New York and New Jersey. One of the most heavily used systems in the country, this network of tunnels, bridges, and terminals at the heart of the region's commercial infrastructure moved more than 254 million vehicles in 2007.

The three Staten Island Bridges - the Bayonne, Goethals and Outerbridge Crossing, link New York and New Jersey. In 1921, the Union County Board of Chosen Freeholders began a movement to have a bridge or tunnel built across the Arthur Kill. This led directly to separate laws being passed in 1924 by the states of New York and New Jersey authorizing the Port Authority to undertake the necessary studies leading to the building of the Staten Island bridges.