1927 - On November 13, the Holland Tunnel opened to traffic. It was the first mechanically ventilated underwater vehicular tunnel, and it was also the first Hudson River crossing in New York City.
1928 - Both the Goethals Bridge and the Outerbridge Crossing opened on June 29, marking the successful completion of the Port Authority's first bistate development project.
1931 - The original one-level, six-lane roadway of the George Washington Bridge opened to traffic six months ahead of schedule for less than the original $60 million budget. To handle the traffic increases, lanes were added in 1946. In 1962, the lower level of the bridge was completed, opening up six more lanes and increasing the bridge's capacity by 75 percent, making the GWB the world's first 14-lane suspension bridge.
The Bayonne Bridge was the third bridge completed by the Port Authority, connecting Staten Island, New York to New Jersey. It opened to traffic on November 15, 1931. Four months later, following the same steel arch design, its "sister bridge," the Sydney Harbour Bridge, opened to traffic in Australia.
1937 - On December 22, the first of the three tubes of the Lincoln Tunnel opened to traffic; the final tube opened in 1957. By the 1970s, traffic was so great that the PA opened the world's first contra-flow bus lane. The Exclusive Bus Lane (XBL) is a westbound travel lane that opens exclusively for buses traveling eastbound into New York City. This lane serves more than 1,700 buses, carrying more than 62,000 passengers to midtown every weekday.