The American Institute of Architects is looking to supplant the idea of replacing the Gowanus Expressway with a tunnel, and instead proposes a suspended highway and formation of a Gowanus Greenway. In 2006, the Dept. of Transportation gave a green light to a $12.8 billion proposal to build a 3.5 mile, seven lane tunnel underneath the Brooklyn Waterfront and then destroying the elevated highway. The plan for a Gowanus Tunnel appears to be in perpetual stall though, and would take approximately 15 years to finish.
According to the Daily News, the alternate plan proposed by the AIA would move the route that connects the Verrazano Bridge to the Brooklyn-Battery Tunnel from the Gowanus Expressway that runs over 3rd Ave. to a cable-suspended highway over 1st Ave. The space between the two avenues would then be transformed into a greenway with parks and bike lanes. The designers are going to start actively pitching the plan to state and city officials soon.
At this point, the only certainty regarding the Gowanus Expressway is that it will continue to be used for some time before it is replaced, unless it actually falls apart first. NYC Roads has a complete history of the Expressway that displaced many Brooklyn residents and cut off many more from waterfront access. The history is followed by a number of proposals for improving or replacing the Gowanus Expressway.