Alexandria officials are about to consider a developer's bid to build nearly 2,000 houses and a town-center-style commercial complex on a 300-acre former railroad yard that is one of the last large parcels of open land close to downtown Washington.

A report from the city's planning staff on the Potomac Yard property -- one of the most valuable pieces of undeveloped land on the East Coast -- has recommended that the city approve the plans, which include a 625-room hotel and 1.9 million square feet of office space.

The land, located between the Potomac River and Route 1 north of Old Town Alexandria, was used as a yard by the Richmond, Fredericksburg and Potomac Railroad Co. until the 1980s. At one point the property was considered a potential site for a Washington Redskins stadium, but concerns of area residents put an end to that idea. In 1997, the land was sold to Commonwealth Atlantic Properties Inc., which erected a retail center with stores such as Target and Shoppers Food Warehouse.

The shopping center was pitched as a temporary, 20-year fixture on the property. But it has been so successful, developers say, it might become permanent.

Commonwealth has proposed building on the rest of the acreage a mix of town houses, condominiums and apartments along tree-lined streets, a design intended to be reminiscent of Old Town. The plan also calls for construction of a four-lane road parallel to Route 1 to alleviate traffic.

In a June 3 memo to the city planning commission, Sheldon Lynn, the city's director of planning and zoning, urged approval of the proposal. He warned that if a decision cannot be reached by this summer, the developer could abandon the mixed-use plan and instead use existing zoning to build town houses and low-density commercial development, such as warehouses.

"Many of us in the city think it's time," Lynn said. "Twelve years of planning and discussion is enough. At some point you have to approve something, and we think this is worthy of approval."

The city staff has recommended several modifications to the developer's proposal, including the relocation of some office space to the site of a proposed new stop on Metro's Yellow and Blue lines, the relocation of one of three proposed playing fields and the realignment of the Monroe Avenue bridge at the southern end of the parcel.

Planning commissioners are to vote on the proposal Monday and will forward their recommendation to the City Council for a decision expected in September.

The development company is counting on a favorable outcome, said Richard Gilchrist, the company's president. "Any owner of property can only pursue a plan approval for so long," Gilchrist said.

If the project gets a green light, Gilchrist said, some construction could be expected within two or three years, but building would not be complete for about 15 years.

The plan is being closely watched by residents in the Del Ray neighborhood on the other side of Route 1. Residents say the new shopping center on the site is poorly designed and has brought the kind of traffic problems they had long feared.

"The configuration and design of the center is horrible," said Al Collins, president of the Del Ray Citizens Association. "You have to have a car to go get there. You can't walk from one end to the other. It's one of the worst examples of retail development."

But Collins speaks optimistically about Commonwealth's proposal for the rest of Potomac Yard. The plan, he said, "includes a lot of the amenities that we think are right for the city."