Trees, traffic and the problems of urban renewal were the subjects of the National Capital Planning Commission meeting last week as citizens protested plans for Pennsylvania Avenue and the 14th Street Urban Renewal Area.

"Why do you want to cover up the front of the Commerce Building and the District Building with a lot of trees?" said Harriet Hubbard, of the Dupont Circle Citizens Association. "And why do you want trees in front of the Willard Hotel? We have good looking buildings along Pennsylvania Avenue that don't need to be masked by trees."

If the NCPC was going to approve planting trees anywhere, Hubbard suggested, it would do well "to have the whole FBI building covered with trees until that architectural "mistake could be corrected in the future.

Plans for a heavily tree-lined Pennsylvania Avenue were approved last week as part of a revised preliminary special street plan submitted to the commission by the Pennsylvania Avenue Development Corporation (PADC).

The plan, which covers part of the avenue between 13th Street and East Executive Avenue NW, does not detail the exact location of the trees. This will be determined later, according to PADC officials, who said the agency intends to have special irrigation and soil to ensure the trees' survival during severe dry and winter seasons.

NCPC commissioners contended that trees would enhance rather than detract from the avenue's structures.

Another citizen, Clinton Brown, echoed concern expressed earlier about a PADC proposal to narrow the street by about eight feet, particularly as it might affect traffic in the area around the Willard Hotel at 14th Street and Pennsylvania Avenue.

PADC officials, however, said the intent is to limit traffic in that area, although the agency could decide later to change the street width to accommodate increased use.

"We've asked questions about Pennsylvania Avenue for 12 years, and it's changed and improved because of them," said NCPC Chairman David Childs. "The feeling now is, let's get on with it."

The commissioners also listened to an emotional dispute over development plans for the 1300 block of the Belmont Street section of the 14th Street Urban Renewal Area, which has been slated for clearance and development since 1969.

The city Department of Housing and Community Development now wants to allow the renovation of existing buildings in that block. The NCPC deferred action for a month at the request of the 14th Street Project Area Committee which is now reevaluating the entire renewal plan for that section of the city.