create and protect portable harbors for the 1944 invasion of Normandy. Construction started in March 1952 and the bridge opened to traffic on December 15, 1955, along with a long section of the New York State Thruway from Suffern to Yonkers. New York State Governor W. Averell Harriman signed a bill on February 28, 1956, to officially name the structure the Tappan Zee Bridge. Originally, tolls were collected in both directions. In August 1970, the toll was abolished for westbound drivers, and at the same time, eastbound drivers saw their tolls doubled. The tolls of eleven other New York–New Jersey and Hudson River crossings along a stretch, from the Outerbridge Crossing in the south to the Rip Van Winkle Bridge in the north, were also changed to eastbound-only at that time. Replacement bridge Planning and construction Since the end of the 20th century, calls to replace the aging Tappan Zee Bridge had gone unanswered. The deteriorating structure bore an average of 138,000 vehicles per day by the end of its life, substantially more traffic than its designed capacity. Unlike other major bridges in metropolitan New York, the Tappan Zee was designed to last only 50 years due to material shortages during the Korean War at the time of its construction. In total, the bridge was open for 61 years, 9 months, and 21 days. The new bridge is intended to last at least 100 years without any major repairs. The collapse of Minnesota's I-35W Mississippi River bridge in 2007 raised worries about the Tappan Zee's structural integrity. These concerns, together with traffic overcapacity and increased maintenance costs, escalated the serious discussions already ongoing about replacing the Tappan Zee with a tunnel or a new bridge. Six options were identified and submitted for project study and environmental review. In 2009, the Tappan Zee Bridge was featured on The History Channel "The Crumbling of America" showing the infrastructure crisis in the United States. Many factors contribute to the precarious infrastructure of the bridge, which has been called "one of the most decrepit and potentially dangerous bridges" in the U.S. Engineering assessments have determined that "everything from steel corrosion to earthquakes to maritime accidents could cause major, perhaps catastrophic, damage to the span," prompting one of the top aides in the New York state governor's office to refer to the Tappan Zee as the “hold-your-breath bridge.” A 2009 state report noted that the