PROVIDENCE — At the end of next year, the newly built sections of the relocated Route 195 will be complete, and the existing stretch of highway will be taken out of service, in preparation for its demolition.

Underneath the existing highway lie 19.2 acres of developable land, and by the time the half-mile stretch of highway comes down, the state and city hope to know what will be done with the valuable real estate.

Before it can sell off the land, a partnership of the Rhode Island Economic Development Corporation, the City of Providence and the state Department of Transportation wants to develop a plan outlining how best to carve up, market and distribute the parcels.

Yesterday, the partnership took a significant step toward figuring that out, gathering roughly 40 planning consultants and real-estate analysts from New York, Providence and Boston together downtown to discuss what the city and state want for the land.

The city and state intend to hire a consultant to develop the plan, and interested companies must submit their proposals by July 31.

They will have a difficult job. They will have to meet the desires of the city to increase its tax base and create a mixed-use neighborhood featuring high-rise office development, while balancing that with the state’s need to sell the property for the highest possible return, to help pay for the $610 million highway relocation.

Moving Route 195 south of the hurricane barrier will open up 36 acres of land between Providence’s downtown and its Jewelry District. Eight acres are set aside for two waterfront parks lining the Providence River, potentially linked by a pedestrian bridge, while eight more acres will go to laying new city streets where the highway used to be. The rest can be sold for development.

Many of the most basic details of that sale must still be settled.

The plan’s developers will have to determine the best way to actually sell the land. Should it be done through the standard DOT property-sales auction, or by another means? Is the market for this property national or international? What is the proper city zoning for these parcels?

And once that, and more, is determined, there are seemingly simpler, but equally important questions to be answered, such as whether the land should be sold all at once or piecemeal.

“Do we start left to right? Right to left? Do we put it all out at once?” Robert I. Stolzman, a lawyer for EDC, asked the consultants rhetorically.

The city and state have established a basic vision for what the area should look like once the highway is gone, but that, Stolzman told the consultants, is malleable as well.

The city and state see the 19.2 acres being divided into 20 parcels, ranging in size from 10,000 square feet to 113,000 square feet. In between them, the old roadway pattern that existed before Route 195 plowed through the city would be re-created.

Eighteen roadways will be reconstructed or created anew, nine on each side of the river.

It’s possible, Stolzman said, that some of these streets could be removed or modified if the consultant determines the market would be better served by larger or smaller development parcels.

The location of the two large parks planned for either side of the Providence River are not set in stone either, Stolzman said, though it’s extremely unlikely they’ll be moved.

“If a significant discussion is warranted on relocation or realignment of parks, it is possible,” he said.

In between, the city will hold a planning summit where citizens will be encouraged to discuss the future of the area with city planners. While they will get feedback from these sessions, the city will also be relying heavily on what the consultants have to say about how the city should maintain the zoning flexibility to attract all kinds of development.

“We will be looking for how to regulate development, or how to encourage development to happen,” said city Planning Director Thomas E. Deller.

Applications to develop the plan are due by the end of the month. The contract will be awarded in early September, and Stolzman said the city and state want a plan completed by December.

dbarbari@projo.com