Two separate incidents on the Tappan Zee Bridge called for some emergency maintenance over the past two days.

On average, 140,000 cars, trucks and buses cross the bridge on any given day, but it's what goes under the bridge that had the New York State Thruway Authority concerned on Friday. On a routine check of the bridge?s navigational system, called RACON, a tugboat operator reported a glitch. The boat wasn't picking up the enormous span on its radar. The Coast Guard will be keeping a close eye on boats crossing under the bridge until the radar system is repaired.

Also, a pothole discovered on Thursday illuminated the need for the bridge to be overhauled. When the span was built 50 years ago, the thickness of the deck only had to be a little more than 6 inches. By current construction standards, that deck now has to be 9 and a half inches thick. The Thruway Authority says a contract for about $147 million will soon be awarded to begin replacing the two outer lanes. However, that construction isn?t expected to begin until next year.

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