The Baltimore Beltway can't get much bigger.
Fifty years after construction began on the 52-mile roadway that rings the city, state officials say they're running out of room to expand. Housing developments and suburban shopping centers are hard up against it, with sound barriers holding the line at the edge of people's back yards.
Space is particularly tight on the southwest side through Catonsville, where work to add a lane should be done this fall. There are also plans to add a lane or two to the northeast side when money is available and to the west side by Interstate 70.
But after that, nothing else is planned - meaning officials have to find ways to keep traffic moving that don't involve pouring more asphalt.
"You can't keep widening further and further out," said Doug Simmons, deputy state highway administrator. "The built-up environment on both sides of the Beltway continues to get more dense."
The troublesome west side carries about 178,000 vehicles a day - a volume that is projected to reach more than a quarter-million by 2025. Officials are now addressing the problem by adding a fourth lane to the three-lane outer loop between Frederick Road and Interstate 95, a $55 million project.
The expanded roadway is being built with extra-wide shoulders that can be repainted into a fifth lane eventually, when traffic demands it, provided environmental regulators agree.
"We are working on plans to widen the Beltway to the maximum extent feasible," said state Transportation Secretary Robert L. Flanagan. He said the expansion work still on the books would cost $800 million to $1 billion - the price of widening the west side from I-70 to Frederick Road and widening the northeast side from I-83 to Harford Road.
But that, Flanagan said, is about as big as the Beltway can get, given the growth along its perimeter and air quality regulations that limit highway expansion. Then the state has two main options for addressing future congestion: toll lanes and technology that alerts motorists to traffic jams and helps officials clear blocked lanes faster.
In one toll scenario, on a Beltway with five lanes in each direction, three of those lanes would be free and two would carry a toll. The price of driving in the toll lanes would vary depending on congestion in the free lanes. The more congested the free lanes, the more it would cost to drive in a toll lane, on the theory that motorists would be willing to pay the higher price to avoid the jams.
The money raised would help pay for the final Beltway widening projects on the west and northeast sides.
"It's important to give people choices," Flanagan said. "It's not acceptable to have the only choice to be sitting in a parking lot known as the Baltimore Beltway. People deserve to have alternatives."
While Gov. Robert L. Ehrlich Jr. and Secretary Flanagan have not signed off on the toll lanes concept, it is being given serious consideration not only for Baltimore's Beltway but also for the Capital Beltway, I-270 and I-95 north of Baltimore.
Using technology to combat congestion is already state policy. A key component of that effort is the CHART program, in which employees monitor 62 traffic cameras trained on state highways and dispatch response teams to accident sites.
Since 1997, the average clearance time for an incident on a state highway has been reduced from 45 minutes to 28 minutes - precious time, especially during rush hour. In peak periods, officials estimate that for every minute a lane is shut down, it takes five minutes for traffic to return to normal.
"It's like throwing a rock in a pond," said John Porcari, a former state transportation secretary. "One breakdown ripples throughout the entire system, especially on, say, a Friday afternoon."
`A tremendous load'
Porcari said the state needs to look at a number of measures - from toll lanes and technology to high occupancy vehicle (HOV) lanes and incentives for car-pooling - to really have an effect on congestion. "Each of those separately tends to work at the margins," he said. "But collectively it adds up to something."
Motorists who use the southwest side of the Beltway can look forward to more immediate relief. The roadway is now three tight lanes between Frederick Road in Catonsville and I-95. The state has rated both loops of the Beltway there as "failing" for congestion.
"They could add two lanes, they could double-decker it and it would [still] fill up," said Marvin Meyer, the owner of a Catonsville swimwear shop and a regular Beltway commuter from his home in Pikesville. "There's so many people using it. This road carries a tremendous load."
Construction on the southwest side's outer loop began in 2001 and was supposed to be completed by this spring. Bad weather delayed the work, now expected to be done by fall.