On the drawing board forever, the plan to bring a trolley line to the Twin Cities is starting to look like the costliest public project since the pyramids. The official public cost, according to the Minnesota Department of Transportation, is $548.6 million in public money from various sources. That's more than $48.1 million per mile for the proposed 11.4 miles of track connecting the airport to downtown Minneapolis via the Hiawatha Corridor. To make matters worse, critics of the deal point out that the budget doesn't include millions upon millions in additional public costs. Several naysayers believe that once costs for utility relocation, associated development, and projected operating deficits are tallied up, the line's total public cost will be closer to $1 billion. Add conflict-of-interest questions, cranky legislators, and uncertain federal funding, and you get one big old train wreck.