MADISON, Wis. (AP) – New estimates show Wisconsin’s transportation fund is headed for a $63.5 million deficit by mid-2015.        The transportation fund covers highway projects, provides road aids for local government and funds the Division of Motor Vehicles and the State Patrol. It consists largely of gas taxes and vehicle registration fees.   Gov. Scott Walker’s two-year budget proposal estimated the fund would end mid-2015 $12.6 million in the black. But new data from the nonpartisan Legislative Fiscal Bureau shows gas taxes are expected to drop sharply over the biennium.   The Legislature’s finance committee is set to take up the transportation portion of Walker’s budget on Tuesday. The new estimates mean the panel may have to decide between delaying road work, increasing borrowing, shifting more tax dollars to the fund or increasing gas taxes to fill the hole.