Astorino stood under the bridge with "20/20" correspondent Deborah Roberts during a segment about the dangers of hundreds of bridges throughout the United States, pointing out signs of visible wear and tear that make many people nervous to drive over the Tappan Zee.
Despite some visible deterioration under the bridge, Astorino said engineers have continued to deem the bridge safe.
One bridge expert told "20/20" that as an engineer he refuses to drive over the Tappan Zee, considering it structurally unsound and one of the most frightening bridges in New York. The bridge has been used seven years longer than intended, he said.
Construction of a new Tappan Zee Bridge, costing about $3.9 billion, remains in the planning stages. The new bridge is expected to be completed by 2018.