About those recent headlines about Atlanta’s traffic congestion…
A spate of recent news headlines warned that “LA has worst traffic in the world” and “Atlanta has some of worst road congestion in US.”
Traffic is bad for a lot of folks in these places, no doubt. But exactly how reliable is the info from the study that these articles reference? Turns out, it’s pretty questionable.
City Observatory (source of some of the best urbanism writing out there) has cast a keen and skeptical eye on the Inrix report that spurred those headlines. They’ve found that it greatly exaggerates the cost of road congestion. It also gives too much weight to the longest of commutes, and shows a bias against relatively-compact city centers.
After a very thorough investigation of the data, City Observatory decides that Inrix is “chiefly interested in generating headlines, rather than providing the kind of analytical tools that could help inform policy choices.”
Ouch! But it’s a fair criticism. We need information that can be used to make effective changes to our cities, not just attention-grabbing headlines.
And we need traffic reports that understand the important relationship between land use and transportation. Something that’s become a common refrain among urbanists is “a good land use plan is the best transportation plan.” Meaning: the distance between our homes and destinations is a big player in commute times, which in turn affect congestion stats (consider that a group of people driving 30 miles instead of ten miles to work is going to have a chance to congest more sections of regional roadway during a day).
The Inrix report on traffic doesn’t mention residential sprawl or job sprawl or car-centric development. That’s a red flag for me. It means the information we’re getting on road congestion is missing some essential context.
The giant scale of the Atlanta region plays a part in congestion stats
Congestion is not all about road design — even though that’s what often gets implied by traffic reports. When an urban region like Atlanta is large in scale and is filled with places built specifically for car mobility alone, road design can only do so much to alleviate commuter pain.
For a look at what I mean by scale, let’s turn to a 2016 Brookings report on commuting in US cities. Here’s what it has to say about the part that the length of commutes can play in traffic statistics:
Metro areas vary considerably in terms of size, infrastructure and development patterns, and distribution of people and jobs. These differences lead to differences in typical commute distances across regions. In the Atlanta metro area, which spans 29 counties and contains more than 5 million people and 2 million jobs, the typical commute distance is 12.8 miles.
As you can see from the Brookings report’s list of the longest average US commutes by urban region, Atlanta comes out on top of the heap. That distance of commute plays a part in our congestion statistics, as the people with the longest drives are skewing the average upward.
1. Atlanta-Sandy Springs-Roswell — 12.8 miles
2. Dallas-Fort Worth-Arlington, TX / Houston-The Woodlands-Sugar Land, TX (tie) — 12.2 miles
3. Phoenix-Mesa-Scottsdale, AZ — 11.4 miles
4. Nashville-Davidson-Murfreesboro-Franklin, TN — 11.0 miles
5. Detroit-Warren-Dearborn, MI — 10.4 miles
This map of job density in the Atlanta region gives you a look at exactly how long those farthest, outlier commutes can be. The dark blue areas on the map show where the highest densities of jobs are located. But workers live all over the metro area, some of them traveling very long distances.
And jobs are all over the region as, well outside those dense clusters. A City Lab article addresses that issue, noting that, between 2000–12, “nearby jobs declined in both urban and suburban Atlanta.” The particular dispersion of jobs and homes we have here puts many workers further from their jobs than they could be.
The development pattern of Atlanta produced a massive urbanized area in terms of residential housing. The bulk of workplaces are located in one north-central area, but lots of other jobs are spread out all over as well, putting a lot of Atlantans in a situation where long commutes are necessary. Any study of traffic congestion here has to take this into account. The sprawl of our region has had an outsized effect on the numbers that describe our average commute times. Understanding this can lead us into a direction where we address planned land use and transportation in unision, creating more efficient commutes.