Lydia DePillis has a very thourough article on DDOT's growing emphasis on walking and biking. It's filled with great tidbits, and you should read the whole thing, but here are a few choice parts.
“We can’t say we want to be more sustainable, but we also want to widen our roads and make it easier to drive, it just doesn’t work that way," [Gabe Klein] said.
DDOT is now retrofitting so many streets for bikes that the agency is trying to figure out how to contract out the work, rather than doing it all in-house. One need: More paint stripers, to keep up with all the traffic flow revisions the agency wants.
The department had bike and pedestrian specialists, but Klein says they were “hampered by the rest of the organization not getting, or prioritizing, bike and ped work"; he gave them more authority and visibility. Klein set a goal of installing 80 miles of bike lanes; 49 have been done.
Assuming he stays on, the biggest obstacle to the development of a walkable, bikeable city is, in many parts of the city, a dearth of places to walk and bike to.
It really makes me hope that Gray keeps Klein on board. If he really thinks bikes are the way of the future, Klein seems like the guy who can get us there. The article also mentions that Klein showed up for the Tweed ride.
On a related note (because they both refer to the Dutch ThinkBike workshop) Richard Layman shares some of what was learned at the workshop. This includes the need for cycltracks and branding them (such as the "Crosstown Connector)