A new study of rush-hour traffic and transit flows across the entire 64-mile Capital Beltway contains the provocative finding that little has in fact changed since 1995 despite dramatic shifts in the region's housing and employment.
That analysis, released by the Metropolitan Washington Council of Governments, might be viewed as a glass half full. The traffic counts taken at 61 points along the highway found that steep job losses in the District, especially in the federal government, did not undermine the traditional stream of workers commuting to employment inside the Beltway, indicating that existing transit lines and car-pool lanes continue to get good use from commuters.
Or the results might be a glass half empty. The flat traffic counts mean that most of the region's rapid development -- and worsening congestion -- is occurring where the transportation network is ill-suited to accommodate it.
"The growth in employment and people and traffic is focused on the Beltway or outside the Beltway and not crossing into the central core," said Ronald F. Kirby, the council's director of transportation planning. "The region is growing, but we don't have any growth where we have our major transit investments."
During the three years since the last cross-Beltway count was conducted, the region's outer suburbs added 35,000 jobs and 94,000 residents. The new study, which was presented to the council's Transportation Planning Board, is the ninth count of cross-Beltway travel since 1978.
In 1998, when the research was conducted, 509,000 people traveled inbound during an average morning rush hour, a 0.8 percent increase since 1995. This slight rise reflects the growth of employment in the area's inner suburbs, such as Bethesda and Tysons Corner, which compensates for the loss of about 33,000 downtown jobs.
And at a time when several major American transit systems are losing riders, the analysis found that public transportation in the Washington area is steadily used. Rail and bus service across the Beltway recorded a 1,000-rider increase on an average morning rush hour, or about a 2 percent rise.
"It reflects we have an extremely fine transit system and that the quality of transit service is very high," Kirby said.
Transit ridership continues to represent about 12 percent of the inbound travelers who cross the Beltway during morning rush. But that finding disguises a dramatic migration from buses to trains. Metrorail recorded a 14 percent jump, and commuter trains, particularly MARC and Virginia Railway Express, were up 6 percent. Bus ridership, meantime, was down 25 percent.
Much of that shift resulted from the opening of Metrorail's Franconia-Springfield station outside the Beltway, according to Kirby. Buses that once ferried commuters up the Shirley Highway to the Pentagon area have now been rerouted to shuttle riders living outside the Beltway to the new rail station.
The study also reported that the number of cars crossing the Beltway with more than one occupant was also up by 2 percent, reflecting the continued popularity of car-pooling for commuters traveling heavily congested highways such as Shirley Highway and Interstate 66. About 28 percent of the inbound cars had more than one occupant.
This finding came a month after the council's annual review of car-pooling reported that HOV lanes on the Shirley Highway, I-66 and I-270 "continued in 1998 to operate at a high level of service and provide substantial time savings." That study did not consider the car-pool lanes on the Dulles Toll Road, which opened at the end of the year.
Commuters often share rides when they can realize substantial time savings, travel a common route and save on parking fees, Kirby said.
But with scattered development in the outer suburbs and free parking at many work sites, the benefits of car-pooling are few in some of the areas where congestion is growing most rapidly.
Indeed, the study offered stark proof that the area's sharp increase in traffic is occurring almost entirely outside the Beltway, where car-pooling is less practical. The Beltway counts also offer a similar challenge for public transit, which requires relatively dense development and corridors of heavy travel.
"What it really comes down to is that the real strains on the transportation system are on the Beltway and outside the Beltway in terms of congestion," Kirby said. "These are places where it's tough to get people into car pools and onto transit."
He suggested that planners should try to concentrate development along corridors such as I-66 and the Dulles Toll Road so that transit and car-pooling can ease some of the mounting traffic.