In a market driven by private-sector demand, nothing cities do can make new development happen or create redevelopment in older areas. Until private demand is there, everything cities do will fall short.Still, city planners and economic development directors continue to make a living. They do that not so much by working directly on economic development projects but by looking into the future to see what could happen on a particular site and then helping to determine what the city could do to make it more likely to happen.That's what Arlington is doing with its extensive New York Avenue corridor study. It's developing a strategy that could help this area of east Arlington rebound to its once-held economic vibrancy. The target area is several blocks on either side of New York Avenue between Abram Street and Arkansas Lane.The planning effort started in November after the City Council approved a $131,000 contract with consultants. Those consultants have held two rounds of meetings with an advisory committee and interested members of the public. They've come up with a draft plan, but it will go through revisions and more public meetings before it's presented to the Planning and Zoning Commission and the City Council in September.Besides offering ideas for landscaping, corridor entry areas and other aesthetic enhancements, the draft identifies three "opportunity sites" and identifies development projects that could fit there:Corner of New York Avenue and Abram Street: The draft shows a potential grocery/retail site with some residential buildings that also house ground-level retail shops.Corner of New York Avenue and Park Row: The draft envisions restaurants, shops, doctors' offices and a community center/library/recreation center.Corner of New York Avenue and Pioneer Parkway: A potential area for senior apartments and cottages and a retail area, the draft says.It could be that none of this happens, that the report simply takes up space on a shelf. But cities have to be ready for what might happen and have plans to help.Planners and consultants earn their keep by presenting feasible ideas for an uncertain future. Arlington is doing the right thing by studying prospects for New York Avenue.