popa,
The NY State Department of Transportation has a new traffic data viewer! Formerly you had to page through volumes of numbers to get the information you wanted, and to know the unpublished route numbers for some major roads. The busiest part of the BQE (between the Brooklyn Battery Tunnel and the Prospect Expressway) gets about 170,000 vehicles/day and the busiest part of the FDR Drive (Upper East Side) about 180,000 vehicles/day. Neither have much bus traffic. Those two roads just don’t have enough lanes to handle enough traffic to get up to 600,000.
The Lincoln Tunnel gets about 115,000 vehicles a day, and unlike every other major highway, many of them are buses. But remembering that most of those are commuters who are double counted it is doubtful that even it would have 600,000. And it is really three separate roads, not one. (Three tunnels, each with its own approach roads on the Manhattan side.)