OAKLAND -- While Major League Baseball continues to meander in its slow deliberations on where the Oakland A's should call home, an architect in this city is pressing an idea of a new ballpark -- above Interstate 980.

The idea is the brainchild of Bryan Grunwald, 67, of Oakland, an urban designer and planner. Grunwald's proposal calls for a new baseball stadium to be built over the depressed portion of I-980 between 14th and 18th streets. In essence, the bridges at 14th and 18th streets would be widened to connect, creating a solid platform where the stadium could be built.

Sound odd?

Grunwald points to several instances where highways have been decked to install green parks -- such as in Seattle and Phoenix -- and connect neighborhoods.

But a ballpark above a highway with big rigs rumbling past?

Oakland Councilman Ignacio De La Fuente said such an idea has been proposed before, when the city was initially considering ballpark sites years ago.

"That site was looked at," De La Fuente said. "There were businesses over there that were interested in such a thing and we looked at it."

De La Fuente said eventually the idea was turned down for other sites.

In December, Oakland unveiled three sites in Jack London Square -- Howard Terminal at the Port of Oakland; Jack London Square North, an area bounded by Jefferson, Market and Second streets and Interstate 880; and Victory Court, between Oak Street and the Lake Merritt Channel.

City leaders also listed the current Oakland-Alameda County Coliseum site as a potential area for a new stadium, but that idea has received the least support.

Perhaps the biggest barrier the I-980 site would face would be getting the air rights -- rights to build above a highway -- from the Federal Highway Administration and the California Department of Transportation. It could take years to get those rights, and there is no guarantee they would ever be given.

Doug Boxer, who cofounded the group Let's Go Oakland -- a collection of business and community leaders trying to keep the A's in town -- said the city and Major League Baseball have already put in a lot of time studying stadium sites, and that adding another now may only bog down the proceedings.

"The city and Major League Baseball have been engaged in a process that's now 18 months old," said Boxer, who also sits on the city's planning commission.

Boxer said a lot of questions exist concerning the financing, infrastructure and timing of the I-980 ballpark proposal, and time may be of the essence when considering a new stadium in Oakland.

Grunwald disagrees.

He said he believes his idea could be built within five years and would be an ideal fit for the city and team -- with the location of the ballpark downtown, a lot of retailers and restaurants surrounding the area and plenty of existing parking in downtown garages.

Grunwald said he thinks the ballpark could reunite West Oakland with downtown, a schism created when I-980 was built.

Eric Angstadt, planning director for Oakland's Community and Economic Development Agency, said the idea of building a ballpark on top of I-980 had been looked at when the city and Major League Baseball began looking at sites but was dismissed because it did not meet certain requirements. He did not elaborate on those requirements.

Angstadt, however, did add that the idea to bridge the two sections of town would be something to explore.

"The idea of reconnecting West Oakland with downtown makes sense from a planning perspective and from several other perspectives," Angstadt said.

"The idea to do that by roofing the freeway with a public space is one way to do that."

Grunwald already has put on several presentations to community and business groups and said he has received mostly positive feedback.

The Jack London District Association, West Oakland Neighbors, Oak Center Neighborhood Association and the West Oakland Association have all sent letters to council members and the mayor endorsing the idea of looking into Grunwald's proposal.

"Construction projects that span freeways have been shown to be practical and successful in cities including Seattle, Portland, New York City and Chicago. There are no obvious reasons why such a plan should not be considered here," wrote Ben Delaney, president of the Jack London District Association, to the mayor and City Council in June.

Grunwald said he is trying to meet with top city officials to try and hash out the possibilities.

"I think the A's are a big asset to the city and it would be a shame to lose them," Grunwald said.

However, De La Fuente said all the talk of a stadium may be moot, considering the A's have stated time and again their intentions to move south.

"We keep talking about all these different sites, but all I know is Lew Wolff has no interest in Oakland," De La Fuente said.

"The reality is the A's have not given a real indication they are interested in any site in Oakland."