An article on Philly.com highlights a number of new or expanded highway projects in the US are vastly failing to meet traffic projections:
Before beginning a $2.5 billion project to widen the New Jersey Turnpike, turnpike officials said the construction was necessary to reduce existing congestion and to cope with future traffic.
“Turnpike traffic is on the rise,” the state Turnpike Authority said in its justification for the project. “By 2032 northbound traffic volume is expected to increase by nearly 68 percent [above 2005 levels]; southbound traffic is forecasted to increase by 92 percent.”
Now, one-third of the way through that 27-year forecast, turnpike traffic is actually about 10 percent lower than it was in 2005.
And this particular project is hardly a one-off:
Similar traffic declines have occurred around the region, challenging long-established assumptions about the need for bigger highways and bridges.
“If these trends continue, it would definitely change the way we need to plan for our transportation future,” said Chris Puchalsky, associate director of systems planning at the Delaware Valley Regional Planning Commission. “But I think the jury is still out on that . . . we need two or three more years of data.”
In 2007, the Pennsylvania Turnpike Commission assumed that traffic would grow 3 percent to 5 percent every year to help pay for debt as it took on a new obligation to contribute up to $900 million a year to fix other roads around the state.
Instead, traffic has been essentially flat.
And when the Delaware River Joint Toll Bridge Commission decided in 2003 to replace the 50-year-old, four-lane Scudder Falls Bridge on I-95 with a $328 million, nine-lane, 180-foot-wide toll bridge, it assumed that traffic would increase 35 percent by 2030.
In fact, bridge traffic has declined slightly and is now below the levels of 2002.
The implications of getting previous projections wrong are significant if funding was expected from toll revenue – which is what has sent a number of PPP transport projects bankrupt. For publicly funded projects though, the failure to meet expected usage hasn’t been so obvious. However, the implications for future transport planning are significant – as we’ve highlighted so many times before. Back to the article:
Highway planners misjudged the future because the Great Recession reduced both commercial and passenger travel, and because of an unexpected drop in driving by young adults.
Now, planners and policymakers must decide whether the last decade was an aberration or the beginning of a new normal.
The decisions are taking on new urgency, as Congress struggles to come up with a new transportation-funding plan by the end of September, when the current one expires. The federal Highway Trust Fund, which pays for road projects around the country, is nearly broke.
“The last decade was a really tough decade for forecasting,” said James W. Hughes, dean of the Edward J. Bloustein School of Planning and Public Policy at Rutgers University.
Traditional expectations of economic growth – which typically fuel traffic growth – were undone by the recession of 2001, the Great Recession of 2007-2009, and anemic job growth for the entire decade, Hughes said.
Add to that the unprecedented behavior of young adults, driven by technology, lifestyle choices, and economic prospects.
“The millennials are really changing the world dramatically,” Hughes said. “We have a younger generation that is driving less and doesn’t want to live in Valley Forge. They want to live in Center City Philadelphia.”
“We had a 50-year period of unrestricted suburbanization, and now there’s a dramatic shift.”
Cars and driving are less important to young adults, who find that trains and buses allow them to work and socialize on mobile electronic devices, he said.
That may mean fewer cars on future roads.
“Nobody was really anticipating this,” Hughes said. “The models have to be recalibrated.”
Some projections have already been lowered.
NZTA have already noted in changes to their economic evaluation manual that traffic growth can no longer just be assumed – and any assumptions need to be proved. It’s a shame though that complex traffic models still seem to defy reality and project traffic growth.
It makes me think about all of our recent state highway improvements, think Newmarket Viaduct replacement, Victoria Park Tunnel, Greenhithe Deviation, Hobsonville Deviation, Mt Roskill extension, Manukau Harbour Crossing Project, SH20-SH1 Manukau Connection, CMJ Improvements and Orewa-Puhoi extension. All have seen increases in traffic volumes in recent years as people shift their travel behaviour however I wonder how they are currently tracking compared to the traffic projections for 2014 when they were proposed and funded. That would be interesting information to get from NZTA.