Study: As D.C. congestion increases, carpools to pick up slack

WASHINGTON — A new report finds that traffic, population and jobs will increase by 2040 in the D.C. region, but that most people will shift away from commuting alone toward carpooling or mass transit.

The report from the Transportation Planning Board at the Metropolitan Washington Council of Governments sees regional population jumping 24 percent, employment 36 percent and lane miles of congestion during the morning rush up 71 percent during the next two decades.

But the report also finds that the share of commuters driving alone between now and 2040 will drop 3 percent, with those people walking or biking in the core and inner suburbs and using carpools and mass transit in the outer suburbs.

The core is defined as Washington D.C., Arlington and Alexandria. The inner suburbs are defined as Fairfax, Montgomery and Prince George’s counties. The outer suburbs include Charles and Frederick counties in Maryland and Loudoun and Prince William counties in Virginia.

But lawmakers and transportation planners debate whether the future really is in carpooling or mass transit.

“The I-95, 395 HOV lanes, the number of people they move per hour in the peak period is four to five times the number you would have in the general purpose lanes. As the time savings for commuters increase between HOV and main lanes in the future, people will choose the carpool option,” says Council of Governments transportation planner Robert Griffiths.

Planning Board member Chris Zimmerman from Arlington believes the report points to a larger issue with mass transit.

“Growth in carpools is a potential consequence of running down the transit system, so it’s not actually good thing. It’s a sign that we have a problem,” he says.

Zimmerman says the region needs to fund Metro to better handle capacity. He says as people stand on trains and reliability becomes an issue, people choose instead to avoid Metrorail. But he argues that funding the Momentum plan, which would add eight-car trains during rush hour by 2025 among other changes, would help convince drivers to shed their cars.

The impact of expanding Metro capacity would decrease congestion on all four local interstates. He also argues that a robust Metrorail system makes good economics because businesses want to be located near Metro stations and people want to live and work near Metro stations.

Griffiths agrees funding is a major component and there is no single solution to fix traffic in the future. The solution will take a mixture of mass transit improvements, HOV or toll lanes, carpooling, and even teleworking.

Transportation Planning Board Chair Scott York, of Loudoun County, agrees that there’s no one fix.

“I think carpooling is a viable. It works for a lot of Loudoun residents. But from Loudoun County to D.C. there is not much room to expand on the Dulles Toll Road, or Route 50 and not much on Route 7 beyond the current plan to expand it to Tysons Corner. So for Loudoun, the future is in the Silver Line and commuter bus options,” he says.

York and Zimmerman agree the challenge to future Metro funding is whether the federal government will agree to provide a dedicated source of funding. The federal government gives employees a transit subsidy to encourage Metro use. More than 40 percent of rush hour riders on the Metro system are federal workers.

Zimmerman argues that with the federal government being the largest single employer for rush hour Metro riders, it’s up to the federal government to provide a reliable, annual funding to help maintain and upgrade the system.

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