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Study says traffic has improved on some sections of the Capital Beltway, but don’t get excited

July 19, 2016 at 12:01 a.m. EDT
Rush-hour traffic on the inner loop of I-495 West. (Juana Arias/The Washington Post)
correction

An earlier version of this story attributed a regional growth and mobility study to the National Capital Planning Commission. It should have been attributed to the Transportation Planning Board of the Metropolitan Washington Council of Governments. This version has been corrected.

It may not feel like it to those sitting bumper-to-bumper every morning, searching Google Maps for an opening or tuning into talk radio for any sign of relief, but on portions of the Capital Beltway in Maryland, traffic has improved in recent years.

That’s according to AAA, which crunched numbers compiled by the Maryland State Highway Administration and found that on the arch of the 64-mile Capital Beltway north of the District, 25,000 fewer cars have used some portions of the interstate each day since the end of the recession.

Less clear is exactly what that means for the majority of Beltway commuters, who probably haven’t experienced any relief from congestion during that time.

Analysts and smart-growth advocates warn drivers not to jump to conclusions — lest they be tempted to hop right back into Beltway traffic. In one firm’s analysis, travel times on the Maryland portions of the Beltway have only gotten worse in the past five years. And the trend observed by AAA may not be specific to the region: The decrease in traffic came amid a plateau in driving nationwide.

Since 2011, the first year for which comparable data is available, travel times on Interstate 495 in Maryland have increased, according to Bob Pishue, a senior economist with the traffic-data firm Inrix. Between Exit 24 in Greenbelt and Interstate 295, travel times in 2015 and 2016 have generally been higher than in prior years.

“In other words, traffic congestion does not seem to be abating,” Pishue said.

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From the automobile advocacy group’s perspective, the data suggests that perhaps the nearly five-year-old Intercounty Connector between Montgomery and Prince George’s counties is pulling traffic off the Beltway — or maybe more drivers are simply telecommuting to avoid the gridlock.

“Motorists are experiencing some big bottlenecks in critical spots on the inner loop and outer loop of the Beltway in Maryland, and drivers are also finding unprecedented relief in other segments of the highway,” said John B. Townsend II, spokesman for AAA Mid-Atlantic.

The Suburban Maryland Transportation Alliance hailed the findings as proof of the connector’s success.

Other groups, including the Coalition for Smarter Growth, which advocates for more transit, say decreased traffic volume is simply following national trends, which show millenials shifting from driving and legions instead flocking to cities and living closer to work. Statistics show that the total number of vehicle miles traveled in Maryland has remained basically unchanged since 2005 — hovering about 56 billion to 57 billion per year.

“I don’t think you can in any way, shape or form claim that the Intercounty Connector was what has created this reduction in small segments of traffic on the Beltway,” said Stewart Schwartz, executive director of the Coalition for Smarter Growth, which opposed the connector. “You have the rise of the millennial generation with much lower rates of holding driver’s licenses and driving and car ownership, the big trend of moving to urban areas, and urban and walkable transit communities. The other piece of it is the collapse of office parks.”

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And just because the number of commuters is down in some areas, that doesn’t mean the ride into the District or Virginia is any smoother for the majority.

Between 2009 and 2015, according to AAA, traffic decreased significantly for travelers on seven out of 10 key Beltway corridors or interchanges in Montgomery County. The same was true of 10 of 20 interchanges in Prince George’s County.

But for most Beltway travelers, the shift in traffic patterns hasn’t made for shorter commutes, according to traffic data.

On the inner loop in Virginia, for example, travel times jumped significantly in April compared with previous years. They also spiked on portions of the outer loop in Virginia in May.

Some of the increased travel times could be attributed to what transit analysts call “pinch points,” such as development at National Harbor. There was a big jump — 26,000 daily commuters — just north of the Woodrow Wilson Memorial Bridge, perhaps, in part, because of the opening of the National Harbor complex, within eyesight of the bridge.

“It’s going to get even worse when the casino comes online,” AAA’s Townsend said, referring to MGM National Harbor, set to open this year.

The other area where there was a steep increase was upriver, where the Beltway crosses the American Legion Bridge after looping through 22 miles of Virginia. It got particularly thick — a 13.5 percent increase — just below the intersection with Interstate 270 in Maryland.

Rich Parsons, vice chairman of the Suburban Maryland Transportation Alliance, said the data suggests that road capacity should be increased elsewhere along the interstate. He pointed to bottlenecks on other parts of the Beltway where additional lanes could ease traffic congestion.

“If you look at most of the traffic bottlenecks in the Washington area, the American Legion Bridge and I-270 . . . where we fail to widen or provide sufficient capacity, you create a chokepoint,” he said. “And that’s what has happened.”

Schwartz warned against drawing any premature conclusions about road capacity from a single set of data.

“It seems like quite the risky approach,” he said. “There are plenty of studies that show that adding lanes in metropolitan areas does not have a long-lasting effect or benefit. In the short term, people will change their route or commute. People will go to that new capacity and fill it up again.”

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And Rob Puentes, president and chief executive officer of the Eno Center for Transportation, said the variety of new transit options — including ride-hailing and carpooling services — has probably contributed to the drop in traffic as well. He pointed to data showing that Intercounty Connector revenue fell short of projections from 2009.

“I think it’s still wrapped up in a lot of these larger trends,” he said. “I have no doubt that the Intercounty Connector has something to do with it. I’m sure it’s not right to say it’s the only thing that’s responsible. It doesn’t seem to be a relief valve for me.”

One point made clear by the study: Overall Beltway traffic shows no signs of slowing in the long run.

Townsend said Beltway traffic has increased by 318 percent since the highway was completed 52 years ago, and he pointed out that traffic in the region is expected to grow 37 percent by 2030.

“As a result, most of the Beltway will reach ‘stop and go’ conditions (with average speeds less than 30 MPH) and Metro trains and platforms will be packed,” according to a report by the Transportation Planning Board of the Metropolitan Washington Council of Governments.