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

Have you ever heard someone say that building a new transit line will increase ridership by so many thousands of riders?

An ad for DC's new Silver Line shows riders dancing into the train. Photo: WMATA
An ad for DC's new Silver Line shows riders dancing into the train. Photo: WMATA
false

Jarrett Walker at Human Transit calls folks who subscribe to that idea "infrastructurists," and he says it's a mistake to attribute too much importance to physical infrastructure. In the end, it's service -- which can be facilitated by new infrastructure -- that influences ridership.

The "infrastructurist" mentality was on display, Walker says, in a recent study published by the Transportation Research Board, which Streetsblog covered in July. The authors examined why some transit lines attract more riders than others.

Based on the transit lines they studied, the authors did not find that speed, frequency, and reliability "individually had a statistically significant effect on ridership." But Walker says there's plenty of evidence demonstrating the effect of service quality on ridership:

While this dataset of new infrastructure projects is too small and noisy to capture the relationship of speed, frequency, and reliability to ridership, the vastly larger dataset of the experience of transit service knows these factors to be overwhelming. What's more, we can describe the mechanism of the relationship, instead of just observing correlations: Speed, frequency, and reliability are the main measures of whether you reach your destination on time. Given this, the burden of proof should certainly be on those who suggest that ridership is possibly unrelated to whether a service is useful for that purpose.

Note the word choice: To the infrastructurist, speed, frequency and reliability are dismissed as operational, whereas I would call them fundamental. To the transit customer who wants to get where she's going, these "operational" variables are the ones that determine whether, or when, she'll get there. It doesn't matter whether the line is at-grade or underground; it matters whether the service achieves a certain speed and reliability, and those design features are one small element in what determines that.

Walker has some additional critiques of the study that he says arise from the "infrastructurist" point of view. It's an easy trap to fall into, he says.

Elsewhere on the Network today: The Political Environment explains the psychology behind Wisconsin's rush to spend big money to reduce the "rush minute" -- the suburban Milwaukee car commuter's version of rush hour. Pedestrian Observations discusses the pluses and minuses of locating rail alongside a road right-of-way. And Better Institutions says U.S. DOT's pronunciations about recovering driving levels are misleading.

Stay in touch

Sign up for our free newsletter

More from Streetsblog New York City

In With Flynn: New DOT Commissioner Wants To Be ‘Bolder, More Ambitious’

Up close and personal with the 46-year-old native New Yorker and Met fan who wants to carry out Mayor Mamdani's vision for transportation.

January 2, 2026

Mamdani Commissioner Pledges to Hold App Companies Accountable for Road Safety

DCWP Commissioner Sam Levine pledged to crack down on app companies that pressure delivery workers to use e-bikes and cars recklessly.

January 2, 2026

Friday’s Headlines: A Very Streetsblog Inaugural Edition

Mayor Mamdani will govern in prose, thank you very much. Plus other non-inauguration news.

January 2, 2026

New Year, Same Carnage: One Killed, Another Badly Hurt, By Hit-and-Run Driver in Queens

The driver of an SUV struck two men in Queens early on New Year's Day and kept on driving even as one of the men died and the other was gravely injured.

January 1, 2026

New Year’s Headlines: New Mayor Edition

Happy New Mayor! Plus other news.

January 1, 2026

Mamdani Picks Mike Flynn for DOT Commissioner — And Put Him Center Stage at his Swearing In

Flynn worked at DOT from 2005 to 2014 on pedestrian and bike projects and capital planning.

December 31, 2025
See all posts