The coalition celebrated its 10-year anniversary last year with the 600th municipal adoption of "Complete Streets," Millar says, adding that 28 state DOTS have an official policy. One of those states is Georgia, which adopted its own "Complete Streets" policy in 2012. "This is more than pages in a manual," say Russell McMurry, GDOT's director of engineering, and Gerald Ross, chief engineer, in a statement. "It is confirmation of an ever-changing culture; an acknowledgement that our transportation system should be more than its least common denominator; a recognition that the straightest route between two points may not be everyone's desired route. It is a state of mind."

The mind-set is influencing major projects, such as Maryland's planned 16-mile light-rail Purple Line, for which four P3 teams were recently short-lifted. In analyzing alignment and various properties and land parcels, highway and transit engineers worked with architects on a proposed library to resolve a potential conflict, says Marcia Kaiser, managing principal for place-making with Parsons Brinckerhoff, Maryland DOT consultant.

"We've done studies [in which] our client may be the DOT, but we're looking at the corridor for a quarter mile on each side," says Kaiser. "This used to be about a transport planner and a bunch of engineers. Now, we work with land-use planners, economists, marketing analysts, landscape architects. It's about everything coming together in a holistic viewpoint."

That holistic view should go even further, says Mike Hancock, AASHTO president. "Many of these trends are currently manifest in metropolitan planning, but they need not be limited to there. We must think holistically when we plan transportation in all regions."