MANHATTAN – Why stop at the Hudson River? The Bloomberg administration is exploring a plan to expand the 7 train to New Jersey, according to a report in The Wall Street Journal. The plan, which has only been under discussion for a few weeks, would be to take some of the $3 billion in federal funding set aside for the now-canceled ARC tunnel. The money would be used to build a new tunnel under the Hudson, and connect the 7 train with New Jersey Transit rail links in Secaucus.