Skip to Content
Streetsblog New York City home
Streetsblog New York City home
Log In
Streetsblog

How Flawed Formulas Lead Down the Road to Sprawl

The new CEOs for Cities report on the misguided metrics that fuel sprawl is getting a lot of attention today on the Network and in local media.

Bike Portland and The Infrastructurist are both featuring the study, which found major flaws in a metric that's widely used to justify road expansion. Several local press outlets ran stories about it under headlines like, "Sacramento traffic not so bad, really."

As Noah reported yesterday, "Driven Apart" author Joe Cortright takes aim at the use of the Travel Time Index, a measurement that emphasizes traffic congestion while ignoring total travel time. The outcome is easy to predict: Calls to relieve congestion by widening roads, which leads to spread out development and longer car trips. But if we instead emphasized total travel time, Cortright shows, the way to achieve better commutes is to build more compactly.

false

I've seen the same logic that underpins the Travel Time Index guide transportation policy decisions, and I wanted to share an example of how this undermines cities and sustainability at the local level.

This summer I worked in the air quality division of the metropolitan planning agency in Northeast Ohio -- known as NOACA. NOACA is the local agency responsible for disbursing federal highway dollars. To a certain extent, its actions are governed by a series of federal directives.

While I was at NOACA, we hired an "air quality planner" whose main responsibility was to perform an analysis mandated by the feds to measure the air quality impacts of every proposed road project.

The problem was, the analysis inevitably concluded -- without fail! -- that expanding a road would reduce air pollution.

That's because the formula only accounted for short-term air quality impacts. Any given road project was likely to reduce congestion in the short-term and provide an immediate reduction in vehicle emissions. But the formula ignored long-term impacts of highway expansion -- sprawl, longer commutes -- which run directly counter to the cause of air quality. The formula simply wasn't sophisticated or far-sighted enough to account for this type of effect.

Yet transportation and planning agencies use this federal formula to guide highway construction decisions across the country. Looking at development patterns over the last several decades, I guess that shouldn't be surprising.

So thank goodness for the CEOs for Cities report, pointing out the absurdity of an entrenched way of looking at how transportation works. Hopefully, this report reaches willing ears in Washington and in local governments. Just imagine all the ways those federal dollars might be put to better use actually reducing air pollution.

Elsewhere on the Network today: Rights of Way outlines a campaign to pressure the Maine Turnpike Authority to divert some of its revenues toward a successful commuter bus service rather than spend ten times that amount on a road widening. Publicola asks why Portland seems to edge out Seattle in the "cool" cities matchup (the answer has to do with sustainable infrastructure). And Grist chats with Congressman Earl Blumenauer about the Obama administration's Sustainable Communities Initiative.

Stay in touch

Sign up for our free newsletter

More from Streetsblog New York City

Security Blanket: Will NYPD Smother Mamdani’s Love of Transit and Bikes?

Zohran Mamdani likes taking the train and riding a Citi Bike — but the demands of being New York City’s mayor may not be compatible with his transit habit.

November 18, 2025

Gov. Hochul Vague on Free Bus Plans As Her Open Budget Salvo Nears

Hochul has said she would neither support a plan that would deprive the MTA of a key revenue stream — fares — nor would she raise taxes to make up for the missing swipes.

November 18, 2025

Report: Traffic Injuries Increase Near Amazon Last-Mile Warehouses

Injuries are increasing near last-mile warehouses and advocates want to change the model for more accountability.

November 18, 2025

Trump Admin Seeks To Decimate Federal Transit Funding

"When you're talking about taking away money from transit, your proposal is flawed from the get-go," said one expert.

November 18, 2025

Tuesday’s Headlines: Soft Focus Edition

The DOT unveils its latest effort to get car drivers to stop killing us. Plus other news.

November 18, 2025

Delivery App Regulation Should Learn from Commercial Carting Reform

Third party delivery apps say they have no ability to police the very system they created — while the city's patchwork regulation isn't addressing the root of the problem.

November 17, 2025
See all posts