Article: Ask GGW: Why can’t Metro keep more trains on the Blue Line? – Greater Greater Washington.
Starts as a simple question and goes from there. Perfect illustration, graphically, of what happens when a line splits or combines which is a theme Jarrett Walker has talked about in the past.
Article: 24 hours of transit in Greater Toronto (visualization).
If you look at the related vids when this is done, McGill’s +ram has also done one for Montréal’s STM.
Number of Bicycle-Related Crashes by Location 2007-2011.
Number of Pedestrian-Related Crashes by Location 2007-2011.
ACOG is doing some nice work with ArcGIS Online. Two examples. Click through to get the interactive versions.