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Is less gridlock a sign of slow growth, or just fewer cars?

While most of us view traffic congestion as an inconvenience (or worse), at least one company views congestion as a symptom of a healthy economy. It appears both camps are probably correct, although increases in public transit ridership, bicycling and other alternative means of transportation could make the latter slightly less telling.

On Monday, INRIX, the Seattle company that collects and analyzes traffic data from many millions of mobile phones and vehicles, released the latest version of INRIX Gridlock Index, which the company claims serves as an indicator of economic strength. Essentially, the logic goes, a smaller increase in the amount of time people are stuck in traffic means a smaller increase in the number of people on the roads trying to get to work or to the mall to buy things. The report quotes INRIX CEO Bryan Mistele offering a cautiously optimistic outlook on the situation:

“The good news is that IGI continued to show signs of an economic recovery. However, it’s less robust than we all would have liked, or expected, as we head into 2013. In fact, some of the lower IGI scores we saw from last November are flashing yellow warning lights – for these local economies and possibly for the nation as a whole.”

Among those slower-than-average growth cities are Atlanta, Chicago and Detroit. INRIX points to Chicago’s slow growth as providing support for at least on negative report on the city’s economy. In Atlanta, on the other hand, INRIX claims its data might act as a damper to reports of faster-than-average economic growth in the region.

Source: INRIX
Source: INRIX

So, is INRIX’s assessment correct? Perhaps.

Historically, at least, congestion does appear to be a side effect (although certainly not a cause) of thriving economies. According to Florida Atlantic University professor Eric Dumbaugh in a June article in The Atlantic Cities, as per capita driving delay goes up, so does per capita GDP:

Source: Eric Dumbaugh / The Atlantic
Source: Eric Dumbaugh / The Atlantic

However, as Dumbaugh notes, there is an upward trend in workers — especially younger workers — eschewing both suburbs and cars by living in urban areas and choosing to commute via public transportation or, in a growing number of cities, bicycle. In a city like Las Vegas, for example, public transportation isn’t very good, but an attempt by Zappos CEO Tony Hsieh (s amzn) to gentrify the downtown area (and move his company’s headquarters, along with nearly 2,000 employees, there from the suburbs) could help take drivers off the road even as economic activity picks up.

Statistics on public transportation support this claim. According to the American Public Transportation Association, nationwide ridership had been steadily increasing since the late 1990s before taking a pretty sharp nosedive at the height of the recession in the first quarter of 2009. Since then, however, rates have been on the rise again. Even car-centric Los Angeles has seen an uptick in public transit usage, as has Chicago.


Source: INRIX
Source: INRIX

In fact, when charted against employment statistics even INRIX found that congestion rates have fallen along with the unemployment rate. INRIX suggests that discouraged workers might be driving down congestion rates, but an alternative reading would be that people returning to work are increasingly choosing alternative means of transportation to save money or lower their carbon footprints. According to 2011 statistics from the U.S. Census Bureau, 9.7 percent of American workers carpool, a combined 3.4 percent walk or bicycle, and 4.3 percent work from home.

Looking at these numbers, at least, it’s difficult to say how good a measure of economic health congestion actually will be going forward. It certainly seems like a valuable data point and one worth considering in economic forecasts — especially as companies like INRIX are able to make traffic-data analysis so much more accurate — but it almost certainly doesn’t tell the whole story. Cities are complicated entities, and as more Americans choose to drive less, or just smarter, we’ll likely need to figure out new ways of assessing how vibrant they really are.

Feature image courtesy of Shutterstock user Aaron Kohr.

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