Numbers Don’t Always Give Us the Bottom Line for Transportation Plans

Dear Dr. Gridlock:

This area will be in gridlock until we use satellite computer technology to analyze, prioritize, subsidize and design our transportation infrastructure. I say this after attending over 100 hours of citizen input sessions on everything from interchanges to tow trucks.

I have worked in road construction on and off for over 40 years. I am also a driver on these same roads. We need a better way to keep people moving.

Gary Nicely,

Sterling, Va.

The writer wants us to put our money into rational choices, grounded in data. In today’s world, there are more opportunities to do that, but there also are plenty of very rational people who think data-crunching has its limits.

I’m not about to argue for whimsy when investing billions of tax dollars in transportation programs. (Though I am getting a little impatient waiting for my jet pack.)

In fact, I’ve seen the value of aerial photography in tracking congestion hot spots, of computer modeling in anticipating the traffic patterns at new interchanges and of GPS data in creating a world of real-time traffic maps, highway information signs and navigational aids.

I’ve been on the road with a Maryland State Highway Administration crew in a teched-up truck, crammed with cameras and sensors, that gives engineers a data assist in managing infrastructure decisions.

During the fall holiday season, I saw how travelers benefited from traffic data that can predict when and where bottlenecks will develop. That same data can be used to build cases for long-term improvements in the travel system.

Among the region’s governments, Virginia has gone the furthest to tie decisions about the transportation network to measures of greatest need and greatest impact. In response to a law passed by the General Assembly in 2014, Virginia’s transportation officials have been developing a scoring system to evaluate which projects are most worthy of public investment.

Makes sense, right? Scoring takes the politics out of the decision-making.

Well, not so fast. Turns out there’s plenty of room to debate which criteria should get the most weight in a scoring system.

In built-up Northern Virginia, the formula puts a huge emphasis on congestion relief, but there was considerable debate over just how huge that emphasis should be.

With congestion relief counting for 45 percent of a project’s total score, your transportation network could tilt toward big highway programs. The public could wind up pouring money into projects that reproduce some of the same old problems that developed with the 20th-century transportation network.

During one of my online chats, smart-growth advocate Stewart Schwartz described the concern about highway expansion programs: “We know that ‘if you build it, they will come.’ It’s well documented that new highway lanes in metro areas can fill up in as little as five years due to ‘induced traffic.’ ” (If you give drivers more lane space, it won’t be long before they fill it up. Then what?)

“Those pushing ‘congestion reduction’ are just looking to expand highway lanes and are only looking at the short term,” Schwartz said. “They are failing to look at the bigger picture of how land use, technology, and transit, walking and biking can reduce the amount of driving for the short, medium and long term.”

But in the long term, as the far-sighted economist John Maynard Keynes observed, “we are all dead.” Today’s commuters — today’s taxpayers — crave those short-term solutions. Short term as in “Now!” And the vast majority of those commuters/taxpayers are drivers.

Many want scoring systems tilted toward doing the greatest good for the greatest number, and they’re the greatest number.

They’re part of the travel constituency that Bob Chase of the Northern Virginia Transportation Alliance is hearing when he argues for a new Potomac River crossing, the rapid widening of Interstate 66 inside the Capital Beltway and other high-impact road projects.

No matter how rapidly a project can be built, it’s supposed to last a long time, and that gets us to another challenge for data-driven decision-making.

No matter how good the number-crunching today, the planners are making educated guesses about how the results will apply decades from now, as their projects mature. Many times, changing realities intrude on the trend lines the planners developed.

The economy gets better or worse, areas develop in unanticipated ways, businesses and government offices relocate, commuting habits change, or technology opens up new travel options. Plus, an optimism bias can affect the humans who use the travel data to anticipate the popularity of their projects.

If all these complications leave you confused and frustrated about our ability to design the future, you’ve got the right idea.

Till we’re all dead, you can trust that Nicely’s conclusion will remain relevant: “We need a better way to keep people moving.”

Photo courtesy of Manuel Balce Ceneta/AP. Click here to read the original story.