When it comes to the public realm, Atlanta has too long settled for good enough. Recently, the city has worked with a private entity —- the Piedmont Park Conservancy —- to create a great public space in Piedmont Park. It has partnered with the Midtown Alliance to develop wonderful streetscapes.

About three years ago, the city of Atlanta committed to the creation of a spectacular public space called the Atlanta Beltline. The project would transform a 22-mile circle of largely abandoned rail corridors into more than 1,000 acres of new parks, 33 miles of trails and 22 miles of greenway transit.

The existing Beltline corridor —- the railroad tracks and adjoining land —- varies from more than 200 feet to less than 50 feet in width. Preserved in its entirety, the Beltline would become Atlanta's defining public space, supporting an arboretum, plazas, gardens and gathering spots. The corridor would connect nearly 2,000 acres of new and existing parks, creating a vibrant emerald necklace that connects 45 neighborhoods through transit and trails.

The city already has invested nearly $100 million to create these parks and connect them with trails to the Beltline. In the coming months, Atlanta BeltLine Inc., the Atlanta agency charged with making the Beltline a reality, will issue its first bonds and most likely acquire the first section of the Beltline —- a 4.5-mile stretch in northeast Atlanta. Park Pride supports this acquisition.

While ABI is set to acquire this corridor, it has yet to develop a plan for what this corridor will look like —- and has no plans for doing so. Instead, Beltline leaders are contemplating preserving a corridor that would be a minimum of 58 feet wide to accommodate two transit lines (35 feet) and a multiuse path (15 feet). The remaining 8 feet, a little wider than most hallways, would be parkland.

Trail. Transit. "Greenspace." Good enough.

Even more disconcerting, ABI is talking about selling off parts of the corridor for development.

Park Pride welcomes development and appropriate density along the Beltline. We don't oppose selling off strategic sections of the Beltline corridor for development. Three years ago we adopted principles that endorsed development, recognizing that it is necessary not only to fund the Beltline, but also to make the parks, trails and transit vital, vibrant and successful.

What Park Pride opposes is letting development take precedence over the public good. We must not sacrifice the integrity of the Beltline to meet short-term financial goals. ABI should sell off potential parkland only as part of a greater plan to create a spectacular public space.

Ironically, it is the greenway —- the spectacular public space —- that will drive economic development. Nobody wants to live next to an active rail line, but the real estate section of the paper is filled with homes bragging about their proximity to parks. National studies show that parks can increase property values by more than 20 percent.

So until ABI has a plan for what the Beltline public space will become, it must not sell any part of the Beltline corridor. The corridor is the Beltline's greatest —- and only —- asset. If preserving the corridor and transforming it into a great public space requires more time and more money, it is ABI's charge to take more time and raise more money.

Selling off parts of the corridor with no cohesive plan will create a Beltline that is "good enough." And when it comes to the Beltline, good enough just isn't good enough.

> George Dusenbury is executive director of the nonprofit group Park Pride.