In case you missed it, my WTOP colleague Michelle Basch, reported on the proposal to get motorists to slow down on DC streets.
It's not just a DC thing, it's global. The European Cyclist's Federation succeeded in getting the European Parliament to pass a resolution calling for a 30 km/h speed limit on residential roadways, and on single lane roads in urban areas that don't have cycle tracks.
Regionally, there have been efforts to get us all to slow down, to stick to the speed limit. Here's a video that provides an easy-to-understand demonstration of how speeds and braking distance really matter.