Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Between 1984 and 2008, expenditure per Interstate vehicle mile traveled fell 10%, while the price of new lane miles and pavement quality more than doubled. To reconcile these trends, we describe an Interstate cost function for a planner who minimizes the cost required to deliver a given level of highway services. Using administrative data, we estimate prices for lane miles and pavement quality and evaluate the user cost of the Interstate. User cost fell by half between 1994–2008, largely due to falling interest rates. In this sense, there is no problem with the cost of the Interstate.