What the New Jersey Turnpike Authority did in 2005 was no different than what almost every other state and regional transportation agency was doing at the time. It predicted that traffic volumes would rise at a healthy clip every year for about 30 years into the future. Then it estimated its revenues based on those figures and issued bonds for a $2.5 billion road widening project.
Today we know that traffic hasn’t risen  at all since 2005. New Jersey’s projections weren’t just a little wrong — they were wildly inaccurate. The bonds were predicated on a 68 percent increase in traffic by 2023. It’s not going to happen: The Philadelphia Inquirer  reports that turnpike traffic has actually dropped 10 percent since 2005.
Even so, Chris Puchalsky, associate director of systems planning at the Delaware Valley Regional Planning Commission, told the Inquirer that local leaders aren’t blinking.
“We need two or three more years of data” before reconsidering the assumptions, he said.
The Pennsylvania Turnpike Commission made a similar gamble in 2007, when it predicted traffic would rise 3 to 5 percent annually and started issuing up to $900 million in bonds annually for road and transit projects around the state based on those projections. Rather than rising, the Inquirer reports, traffic has been flat. Pennsylvania hoped to repay the bonds with the increased toll revenues and by adding tolls to I-80.
But the additional traffic never materialized, and the Federal Highway Administration rejected the proposed toll on I-80. Now the turnpike is paying much less every year for state transportation projects, but it is still saddled with a rising debt load — $8 billion, according to the Inquirer.
Here’s the kicker. Nikolaus Grieshaber, the turnpike’s chief financial officer, told the Inquirer that Pennsylvania is revising its projections downward. It will now predict a traffic increase of 1.5 percent annually.
Nationally, vehicle miles traveled increased 0.6 percent  last year, so Pennsylvania is still predicting its traffic will increase two and half times faster than the nation as a whole in 2013.