Yet Another Flawed Congestion Report

The new INRIX Traffic Scorecard uses "big" data to calculate congestion costs. Like previous studies, it exaggerates traffic congestion costs and roadway expansion benefits.

2 minute read

February 28, 2017, 5:00 AM PST

By Todd Litman

Mr Doomits / Shutterstock

The newly released INRIX 2016 Traffic Scorecard uses cell phone, vehicle tracking and GPS data to calculate traffic speeds and congestion delays in U.S. cities. But critical analysis by City Observatory researcher Joe Cortright (Yet Another Flawed Congestion Report from Inrix: Big Data Provides Little Insight) challenges the Scorecard's methods and conclusions.

"Two words summarize our reaction to the new Inrix report: tantalizing and aggravating. The tantalizing part is the amazing data here: Inrix has astonishingly copious and detailed information about how fast traffic is moving, almost everywhere. The aggravating part: its essentially just being used to generate scary–and inflated–statistics about traffic that shed precious little light on what we might do to actually solve real transportation problems. Its main purpose seems to be to generate press headlines: 'Los Angeles Tops Inrix Global Congestion Rankings,' 'Atlanta Traffic Among Worst in the World, Study Finds,' and other scary stories."

"One one level, its a truly impressive display of big data. Inrix has compiled 500 terabytes of data, for hundreds of thousands of roadway segments, from hundreds of millions of sources on more than a thousand cities around the globe. That’s a real wealth of information. Inrix casually slips in the factoid that average speeds on New York streets are 8.23 mph, versus 11.07 mph and 11.54 mph in L.A. and San Francisco respectively. But unfortunately, in this particular report, it has chosen to process, filter and present this data in a way that chiefly serves to generate heat, rather than shed any light on the nature, causes and solutions to urban traffic problems. If 'big data' and 'smart cities' are really going to amount to anything substantial, it has to be more than just generating high tech scare stories."

Cortright identifies four key problems with the Scorecard:

Methodology: New and non-comparable, but not significantly different or better
An unrealistic definition of congestion
Exaggerating costs
Ignoring distance, discounting accessibility

The City Observatory gave Inrix a grade of D for the previous iteration of this report. This year they dropping that down to an incomplete. Inrix clearly has a wealth of data that could tell us a lot about how well our transportation systems perform, but so far, it appears that they're chiefly interested in generating headlines, rather than providing the kind of analytical tools that could help inform policy choices.

FULL STORY: Yet Another Flawed Congestion Report from Inrix. Big Data Provides Little Insight

Monday, February 27, 2017 in City Observatory

Transportation North America Traffic Congestion INRIX Congestion Costs INRIX Global Traffic Scorecard View More

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I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

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