Drivers who slog through a snarled commute each day may not believe it, but a new study shows traffic in the region has improved.
The report, slated to be released Wednesday to the National Capital Region Transportation Planning Board, studied aerial photos of about 300 miles of local highways. Overall, it found that traffic declined in the Washington region in 2008 from 2005.
“That’s not to say it’s good,” said Ronald Kirby, transportation planning director for the Metropolitan Washington Council of Governments. “Within that, there are still some areas where congestion got worse.”
Traffic on the stretch of Interstate 395 headed south from Fourth Street Southwest to U.S. Route 1 in Virginia, for example, worsened during the evening rush. It earned the title as the region’s worst bottleneck.
Meanwhile, the nearly 20-mile stretch of Interstate 66 from Virginia Route 234 in Manassas heading east until the Capital Beltway was labeled the worst corridor during the morning commute. Drivers faced delays of 21 minutes.
But the study found the number of lanes identified as congested in the morning and evening commutes dropped to nearly 2002 levels. And the places with the highest traffic density in 2008 still had lower levels than the worst areas three years earlier.
Much of the improvement came because people drove fewer miles. The overall vehicle miles traveled dropped 3.1 percent since 2005, the first decrease since the study began in 1993. Kirby cited the recession and last year’s record gasoline prices as factors.
Transportation experts say reducing the volume of cars slightly during rush hour can speed up commutes. A report commissioned by the Federal Highway Administration said the Washington area could greatly reduce congestion on roads by reducing rush-hour traffic by 10 to 14 percent. If traffic were reduced by that amount, delays could be cut by up to 80 percent, saving millions in wasted time and fuel. It also would increase the number of cars the roads could carry without needing to build roads.
The Transportation Planning Board study found that some regional road improvements have helped, such as a widened ramp onto Interstate 295 in Anacostia that carries traffic from Suitland Parkway to exit to the 11th Street Bridge.
The survey is conducted every three years, Kirby said. It consists of aerial photographs shot in the spring during evening and morning rushes over several days. The analysts then measure the density of cars in each lane to gauge congestion.
WORST CORRIDORS
The aerial traffic study identified the five corridors with the worst delays during the evening and morning commutes.
ROAD / SEGMENT (DELAY)
Morning rush:
1. Interstate 66 / Eastbound from Route 234 bypass to I-495 (21 minutes)
2. Interstate 495 / Outer Loop from Route 201 to I-270 (19 minutes)
3. Interstate 95 / Northbound from Dale Blvd. to Lorton Road (12.5 minutes)
4. Interstate 270 / Southbound from Clarksburg Road to I-270 spur (12.5 minutes)
5. Interstate 395 / Northbound from Franconia Road to Route 7 (11 minutes)
Evening rush:
1. Interstate 495 / Inner Loop from Route 7 to I-270 spur (16 minutes)
2. Interstate 495 / Inner Loop from I-270 spur to University Blvd. (14.5 minutes)
3. Interstate 270 / Northbound from I-370 to I-70 (11 minutes)
4. Southeast/Southwest Freeway / Northbound from Route 27 to Pennsylvania Ave. (10.5 minutes)
5. I-295 Northbound from I-450 to I-197 (8 minutes)
SOURCE: “Traffic Quality on the Metropolitan Washington Area Freeway System,” Spring 2008 report; National Capital Region Transportation Planning Board
