RFK Stadium in 2007. (Katherine Frey/The Washington Post)

Salim Furth, a Capitol Hill resident, is a senior research fellow with the Mercatus Center at George Mason University, where he focuses on urban, regional and macroeconomic trends and policies.

When Orange, Blue and Silver Line Metrorail trains stop at the Stadium-Armory station, they pause at the gates of the two biggest real estate headaches in the District: To the northeast, RFK Stadium sits empty, with Major League Soccer’s D.C. United now basking in the subsidized confines of Audi Field three miles away. And to the southeast is “Reservation 13,” an assortment of underused public buildings anchored by the D.C. jail.

The District’s otherwise-incompatible plans to redevelop the sites have two things in common: Each is visionary and failed to advance. Both approaches represent the grand visions of planners and corporations, and both should be abandoned. Instead, the District should view RFK Stadium and Reservation 13 as a single area and accommodate gradual, market-led development to suit its needs and character.

To replace RFK Stadium, architecture firm OMA New York drew up plans for an athletics complex that would have made a Roman emperor blush. It’s a shocking repudiation of everything learned about city planning since 1960.

Instead of using the land for diverse purposes, it uses it for one. Instead of contrasts, it features uniformity. Instead of blending into the surrounding neighborhoods, it turns inward without a single residence or streetside shop. Looking at OMA New York’s renderings of grand, white structures on a canvas of parkland, one can only see a genuflection to the Chicago World’s Fair of 1893.

Nothing could be further from what District residents need or want.

The District’s “illustrative site plan” for Reservation 13 is far more attractive but has proved equally unattainable; it was written in 2002. It imagines rowhouses and apartment buildings on a grid of side streets, with one or two neighborhood parks. The problem is that the land is occupied by public services. Executing a unified vision requires the District to vacate and level the entire site at once, or to make each part of the project work piecemeal.

A third, better approach would refocus the planning process on the functional roles that the District government would play in the new neighborhood: defining and maintaining streets, connecting utilities, educating children and protecting the environment. The size, form and uses of new structures should be left relatively free. This approach is old. It gave us the beautifully anarchic architecture of East Capitol Street and the dense shopfronts of Georgetown and Anacostia.

These types of gradually built urban neighborhoods have many advantages over the one-dimensional megaproject envisioned for RFK. They typically mix residences with neighborhood commerce and services, providing the sociability and security of 24-hour use. Building styles, sizes and price points differ, accommodating a diverse population.

It also makes sense for developers. Block-by-block construction entails smaller-scale financing, investors aimed at different market segments and a neighborhood that evolves with the city’s needs even as it arises. Developers build to meet demand, so projects mix reasonably well with the existing neighborhood. As the site ages, buildings can be renovated or replaced one at a time.

Implementing the third way in RFK and Reservation 13 would allow the city to welcome any investor, even a small one. The city should determine ahead of time what share of the site preparation and infrastructure costs, if any, it will cover, and offer the same deal to all investors. The usual process — lengthy negotiations between a powerful government and powerful developers — shuts out small-scale investors.

Megaprojects imagine every site as a trendy commercial destination, even when that’s unlikely to succeed. Like RFK itself, OMA New York’s plan makes no pretense of mixing with the neighborhood.

By default, the city has stumbled toward the more modest approach with Reservation 13. The 2002 master plan, now gathering dust, approved the construction of two apartment buildings on parking lots right beside the Stadium-Armory entrance. To open a pipeline of similarly modest projects, the District should push for similar growth at the edges of some of the RFK parking lots.

Leadership must come from the mayor’s office, which seems committed to replacing one misfit stadium with another.