A major repair project on the aging Tappan Zee Bridge is moving forward.

This project, which is expected to cost $100 million, will replace 40 percent of the original decking and will start on the Rockland side. Once complete, the work will continue to the middle of the span. Officials say the current decking has deteriorated primarily from the salt and sludge from the winter months.

The maintenance is being done to make sure the 50-year-old bridge will last a few more years until a decision can be reached on the fate of the span. All of the work will be done from 8 p.m. to 6 a.m. Two lanes on either side will remain open during that time.

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