By Eric Jaffe
CityLab
After years of consistently going up, driving mileage in the United States began to plateau around 2005, and it remains shy of historical per-capita highs—a new normal casually called “peak car.” Still many official traffic forecasts remain tainted by the old belief that car use is always on the rise. The result is that highway expansion projects seem necessary to meet driving demands, and taxpayer money goes to building new lanes instead of maintaining existing ones.
Flawed traffic models aren’t going away anytime soon, but their influence suffered an overdue blow in federal court last weekend, in a case involving the$146 million expansion of State Highway 23 in Wisconsin. Judge Lynn Adelman of the Eastern District Court ruled that officials failed to justify their future driving estimates in the face of peak car trends. As a result, the Wisconsin DOT might not have properly considered alternatives that didn’t involve doubling the lanes from two to four.
Here’s the ruling’s key takeaway:
“If it is true that the defendants’ projection of traffic volumes is flawed, then one of the key rationales for expanding the highway to four lanes will be undermined. If accurate projections are used, it may turn out that an alternative to full-blown expansion, such as installing passing lanes in certain areas and making other targeted improvements, would satisfy enough of the project’s purpose and need to be feasible.”
In practical terms, the decision halts the highway expansion until Wisconsin DOT performs a better traffic analysis, goes through the public feedback process for environmental review, and gets approved by the Federal Highway Administration. (To be super technical: the project could still process, but would have to do so without federal funding.) Given how well the case highlights all the implications of poor mileage forecasts, we took a closer look at the details.
The traffic forecast justified a four-lane highway.
The 19-mile section of S.H. 23 in question connects the small cities of Sheboygan and Fond du Lac. For years local officials have pushed to expand the two-lane, largely rural road into a four-lane expressway. The project made its way into the official transportation queue in 1999 by what looks to be a shady backroom political deal; here’s an internal Wisconsin DOT email, quoted in the new ruling:
“This project was placed in the budget by a certain legislator. That legislator either got the project into the budget in a trade for support of something else or it was his/her hit for the budget. I believe it happened in the caucus process, which is late at night and with only some folks.”
The highway project needed federal funding, so officials had to go through the federal environmental review process under the National Environmental Policy Act (NEPA). Public feedback to an initial draft in 2004 questioned whether traffic levels would necessitate an expansion to four lanes. But that plan met with Federal Highway Administration approval in 2010, then again when updated with supplemental information in March 2014.
The state’s decision boiled down to the belief, based on traffic models, that the existing two-lane stretch of S.H. 23 wouldn’t meet driving demands in the coming years. The table below, from the latest version of the environmental review, shows travel forecasts on various parts of the highway circa 2035.
Read the full article here.