The $5 billion project has been criticized for not including some form of mass transit.
The rush-hour bus lanes, open during peak morning and evening periods on the bridge, will be a short-term answer to the problem.
The buses will run in the lanes usually reserved for emergency vehicles.
The bridge is expected to carry 14 lanes on twin spans.
The bus service that would benefit most immediately is the existing Tappan Zee Express, which carries commuters to Metro-North stations in White Plains and Tarrytown.
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