On the turnpike, meanwhile, $2.5 billion is being spent to add miles and miles of lanes. Some transportation projects, like bridge expansions or upgrades, are driven by safety demands and remain critical regardless of traffic. But the lower-than-expected volumes here and nationwide should have policymakers at all levels rethinking old assumptions about the need for new lanes and routes. The purpose of spending billions of federal and state tax dollars on roads was not to create so much capacity that highways seem like country roads.
That could mean officials favor filling potholes and repaving highways rather than widening them or mapping new spurs. It's similarly smart to increase access points for better use of existing routes, as with the planned junction of the Pennsylvania Turnpike and I-95 in Bucks County.
Such a shift would be well-timed given that the interstate system has aged to the point where billions must be invested just to keep it up. Last month, the issue got attention from President Obama, who proposes spending more than $300 billion over the next four years on roads and bridges - a worthy national priority that should prompt a rare outbreak of bipartisan cooperation in Washington.
Beyond the implications for highway policy, the travel trends demonstrate the importance of continuing to shore up and boost investment in mass transit. As motorists have reacted to gas prices and other costs by driving less, while boomers and young adults have developed new enthusiasm for urban living, mass transit has seen record ridership increases.
In light of that, Gov. Corbett can point to a signal achievement in newly assured funding for SEPTA and other transit agencies, authorized last fall.
For Gov. Christie - who has probably had his fill of traffic jams - it's not too late to craft a progressive regional strategy for improving transit access to Manhattan and other job centers across the Garden State. That could include a restoration of bus and rail service eliminated after the governor cut NJ Transit's funding in 2010. Agency research has shown demand for more service on the Atlantic City Line, for example, which would in turn encourage use of the new Pennsauken station offering connections to the River Line.
Like drivers navigating a highway, transportation policymakers need to watch out for changing traffic patterns.