The Tappan Zee Bridge opened to traffic in 1955 and, until its retirement on October 6, 2017, was a vital artery for residents, commuters, travelers and commercial traffic. The bridge, which was designed to carry up to 100,000 vehicles per day, handled an average of 140,000 vehicles daily, and traffic congestion and delays were regular occurrences. Heavy traffic, narrow lanes and the lack of emergency shoulders often contributed to congestion and frustration for motorists. As a result, the bridge had twice the average accident rate per mile as compared to the rest of the 570-mile Thruway system. In the last decade, hundreds of millions of dollars were spent to maintain and repair the bridge. Had the bridge not been replaced, the cost of maintaining the bridge would rival the costs of a new bridge, with none of the benefits.