Lost in the public announcement of House Speaker Frank Chopp’s vision for the Alaskan Way Viaduct last week was the fact that in addition to the retail and office space that could be stashed under the wall o’ highway (with a park on top), planners are also considering putting residential space there too. Yep, housing. Under the Viaduct. Ron Paananen, WSDOT’s deputy urban corridors administrator, confirmed that residential is a potential use for the Choppway. Says Paananen, “We really haven’t nailed down all the uses it could be. We’re going to be doing some market research to see what the value of that space might be and what types of uses might be attracted to it.” He adds that a number of questions would have to be asked about the potential for putting apartments or condos under a highway, including whether it would fit with the city’s comprehensive plan as well as whether its feasible. The idea of including a mix of uses under the Viaduct is to generate revenue, Paananen says, “So what’s going to be the highest and best use?” While mixed-use development, including residential, is common for projects centered around mass-transit stops, Paananen says he’s not aware of any examples of residential, or even commercial space for that matter, being built under a highway. There’s probably good reason for that.