In my neighborhood, at the intersections where Union and Sackett Streets meet Hicks (both busy thoroughfares that cross over the BQE), construction workers have been ripping up the corners, installing new patches of sidewalk that cut more deeply in the road, thus narrowing the entry and exit points into the crossroads.
They're working quickly. One corner is finished and three more are on their way. From what I gather, the intention is to slow traffic traffic at these intersections. Another person told me this is happening all over Brooklyn. And another suspected it all had something to do with making bikers' lives easier, although I can't see how that would be the case. (Someone always suspects bikers' rights are at the bottom of everything.)