I favor Bob Poole’s solution:
“The longer-term solution is to scrap the 20th-century tax-and-grant system in favor of universal tolling, managed by each state’s Department of Transportation and private toll companies.”
Furthermore, get the federal government out of the business of subsidizing highways altogether and allow the states to privatize them. It would shift the cost closer to home and drastically reduce pork.
Greg Mankiw’s Blog: Bad News for the Pigou Club