Potomac Yard, a proposed redevelopment of the railroad switching area south of National Airport and east of Route 1 in Arlington and Alexandria, made the news recently. It was news not because of the merits of the urban design or planning process underway, but because of an increasing dispute over the density and type of development -- a mix of commercial, residential, civic and recreational uses -- being contemplated.

In an article headlined "Alexandria's Growth Fight Heats Up," Washington Post staff writer Pierre Thomas reported that "negotiations aimed at compromise between developers and civic activists have ground to a tense standstill."

Predictably, future traffic is at the center of the debate, and a forthcoming transportation impact study, being prepared by the Alexandria government, is expected to predict how much or how little gridlock is likely to occur.

The debate also focuses on the impact Potomac Yard might have on "the flavor of Alexandria," a city still viewed by many local citizens as primarily residential.

The developer, Alexandria 2020, a "joint and collaborative" effort of the RF&P Corp. and CSX Realty Inc., intends to build over the next 30 years 17 million square feet of development on 320 acres. According to Thomas, some opponents "are calling for 2 million square feet of development -- not 17 million."

And three Alexandria City Council members have advocated reducing by two-thirds the density proposed in the Potomac Yard corridor. Their plan would allow only 6 million square feet of development, 80 percent to 90 percent being housing.

Given such divergent opinions about development of this strategic site, what is the appropriate course to follow? And how did the current development plan evolve?

From the outset, the developer properly decided to avoid covert, back-room planning. It pursued an overtly public approach aimed at reaching informed, reasoned consensus.

A Citizens Advisory Task Force was established to enable citizens to contribute directly to the planning effort. Public forums were organized to deliberate land use concepts. Over the past two years, newsletters and reports were distributed periodically to the community explaining the Potomac Yard planning process and plan.

At the end of 1989, Alexandria 2020 issued a report showing the overall site plan, prepared under the direction of HOH, an Alexandria urban design and landscape architecture firm.

The plan extends and elaborates upon the existing street grid pattern west of the site, locates a "town center" and two Metro stations along the consolidated rail corridor and provides a north-south avenue for through traffic parallel to Route 1.

A half-mile-long, grandly landscaped boulevard, Canal Walk, would form the pedestrian and vehicular spine of the community. Commemorating the Alexandria Canal, it links together the town center and other public parks but will not carry through traffic.

Another report listed proposed development principles, evaluation criteria required under Alexandria's Coordinated Development District (CDD) and comprehensive city plan. Key principles relating to land use, density, neighborhood definition, transportation and open space include:

A 1-to-1 ratio between housing and office space across the entire site, with density on the Alexandria portion not to exceed 12.5 million square feet of floor area, only a third of which can be office space -- with the remainder to include housing, retail, hotel, recreational, cultural and transit uses.

Five distinct, mixed-use neighborhoods, each encompassing from six to 17 city blocks, with a range of medium-to-high-density housing types, some to be "affordable."

Thirty-five percent of developable site area for parks and open spaces.

Decreased "scale, height and massing" from north to south, except at Metro stations, with required setbacks from the George Washington Memorial Parkway, plus protection of view lines to the Washington Monument, the Potomac River along east-west streets and between the Masonic Temple and Capitol dome.

Upgrading of Route 1, limited vehicular access from Potomac Yard to the existing Delray neighborhood to the west -- only three east-west streets will connect both ways -- and a pedestrian-bike network throughout the site.

Structured or underground parking, rather than on-grade parking, where density makes it economically feasible.

Provision of incentives for use of public transit and reduced dependency on private automobiles.

Phasing and limiting the pace of development so that each phase can proceed only when the developer demonstrates to the City Council that public infrastructure and services are being provided.

Alexandria 2020 has made a reasonable proposal and put forth a responsible plan, one just recognized for its merit by the American Planning Association, which cited the Potomac Yard design in its 1990 awards program as "visionary."

Of course, the current controversy is less about design than about protection of local interests and the status quo.

Citizens to the west and south are understandably nervous about a transformation so far-reaching and so vast. If managed poorly by developer and government, Potomac Yard could precipitate paralyzing traffic gridlock and adversely affect adjacent neighborhoods and property values. Looking north, Alexandrians see Crystal City and, justifiably, shudder.

Yet it is the very far-reaching attributes of the Potomac Yard site that make its intense development appropriate. This site is not just a leftover land parcel slicing into northern Alexandria. It is a regional resource with regional visibility and regional, not just local, potential. Its fate transcends the fate of Alexandria, or Arlington, alone.

Its accessibility to regional public transportation is unique. A stone's throw from National Airport, the site abuts the Potomac River, where future high-speed ferry or water taxi service could be conveniently at hand. It can be directly served by extension of Metro's Blue Line as well as by a commuter rail line station. Route 1 corridor enhancements are already underway, including improved signals.

Here is a metropolitan Washington site, not just an Alexandria or Arlington site, well suited to the urban uses and physical form proposed by its developer. Here one could live and work, walk or ride a bicycle, and not need to own or routinely drive a car for commuting or local shopping. If not here, where else could urban densities possibly make more sense?

Indeed, the gross density proposed, measured as the ratio of total building floor area to total site area, is only 1.2 floor-area ratio, which is not a high urban level. Even subtracting the area of the rail corridor, street rights-of-way and Four Mile Run yields a net density of 1.8 floor-area ration, comparable to the net density of blocks in Old Town Alexandria. Urban net densities commonly range from 2 to 6 and higher.

Significantly reducing the density envisioned is the wrong way to alleviate the anxieties of local citizens.

The developer, public officials and citizens instead should continue their collaboration, mitigating through prudent design tactics and development criteria specific problems that could plague Potomac Yard neighbors if the project is mismanaged.

Transportation policies should encourage congestion-relieving behavior such as car pooling, use of mass transit and non-rush hour work schedules and commuting. Parking spaces should not be built for every conceivable occupant and visitor. Architectural-urban design controls should ensure a humane streetscape, avoiding "Crystal Cityfication."

Wisely implemented with sufficient densities, Potomac Yard can become an attractive urban asset, rather than a liability, both for Alexandrians and for those who live elsewhere in the metropolitan region.

Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.