The proposed solutions, which are to be discussed Wednesday by a regional transportation board, are similar to New York City's plan to charge fees for vehicles entering congested parts of Manhattan. Such tolls already exist in Stockholm and London.

In a report completed last month, planners with the Metropolitan Washington Council of Governments analyzed possible congestion pricing plans. The one deemed most favorable involves putting variable tolls on freeways and parkways throughout the region, as well as all river crossings in the District of Columbia and some other roads.

The tolls would operate with congestion pricing, meaning the price would vary depending on how bad the traffic is. The goal of congestion pricing is to use market forces to keep traffic flowing freely at all times. The tolls would be collected by transponders such as those used for E-ZPass, without the need for toll booths.

Arlington County Board member Chris Zimmerman, who chairs a council of governments task force on congestion pricing, said tolls are the wave of the future.

"It's inevitable that our society is eventually going to have to price our roadways," Zimmerman said in an interview Monday. "There's no free lunch and there's no free ride."

However, he said the report makes clear there are limitations in the potential of tolls to pay for new lanes.

The study looked at several options for adding new capacity and converting existing lanes to tolled lanes, which would continue to be free for buses and vehicles with at least three people.

Only one of those scenarios would pay for itself, however. It would not add any new lanes within D.C., and would charge tolls for all D.C. bridges and freeways and apply congestion pricing to the region's parkways, including the Baltimore-Washington Parkway and the George Washington Memorial Parkway. New lanes with congestion pricing would be added outside the Capital Beltway.

Congestion pricing is already in the works for some highways in the region. Virginia is moving forward with high occupancy/toll, or HOT, lanes on the Capital Beltway and interstates 95 and 395. Maryland is building express toll lanes, which are similar but without the discount for carpoolers.

But implementing the comprehensive network envisioned in the report would require agreement from several different jurisdictions.

The National Park Service, which operates the parkways, has already weighed in with opposition to the plan. In a letter to council officials, the park service said that even though they are used heavily by commuters, the primary purpose of the parkways is "to provide a natural, scenic travel route into the Nation's Capital." Tolling infrastructure could detract from the scenery and would require legislative changes, parks officials said.

Michael Replogle, transportation director of Environmental Defense, criticized the report for focusing on options that would add new road capacity "that will generate more traffic and greenhouse gas pollution."

He said a better option would be to use congestion pricing on all existing regional roads.

Zimmerman agreed that other options need to be considered, beyond what was in the report.

"It leaves open the question, what if instead of doing this we put all the money into public transportation?" he said.

---

On the Net:

Full text of report: