Because the rightwingnut Grover Norquist,

has em by their tiny balls, the Pubs have refused to increase funding for any road/bridge repair maintenance since the NINETY's. As our transportation infrastructure has deteriorated these clowns have remained loyal to the jerk who has WAY more power than he should, AND, they're successfully able to kill any projects that could help the economy, thus hurting their chances in the next election. Now, as cars/trucks get better mileage and the number of miles driven drops, we need the funding more than ever, just to maintain, let alone improve our rapidly crumbling infrastructure, BUT, as always, the Pubs are more worried about politics than serving the people. Nothing new here, but is just another reason why I can't stand 'em.