For as long as most political insiders can remember, the man spearheading regional planning in a land infamous for urban sprawl and perpetual traffic jams has been a tweedy Don Quixote swinging at growth’s downside with a wonkish passion for the big idea. Come next year, Mark Pisano may be focusing more on his pension as he departs the Southern California Association of Governments after 31 years as executive director, the L.A. Weekly has learned.

Pisano is leaving at a time when quality of life here, as measured by housing, air quality, congestion and jobs, has slipped further into arthritic decay in a low-wage McEconomy. California’s initiative against global-warming gases has added another layer of complexity, even as sunny L.A. is forecast to attract a Chicago-size population of 6 million more people by 2025.

It’s not clear whose idea it was for Pisano, one of California’s longest-serving unelected public officials, to go. Los Angeles County Supervisor Yvonne B. Burke, president of the association’s Regional Council, says it was Pisano’s choice, and that the organization, which unappealingly calls itself “SCAG,” will hire an executive search firm to find a replacement.

Pisano declined comment, saying he wants first to inform his 77-person, politician-packed board. He is believed to be pulling down about $250,000 a year.

“It was basically his decision,” says Burke. “Mark is not being forced out. His reputation has moved beyond SCAG, and that reputation demands a lot of appearances and involvement.”

Pisano informed his staff last year, then reconfirmed it at a recent staff meeting that one source described as strange at best: Pisano asked everyone to stand up while affirming a mission statement that commits SCAG to provide “leadership, vision and progress” needed to build “livable communities,” among other goals.

Former SCAG regional president Toni Young had a different interpretation about the shakeup.

Young, Port Hueneme’s mayor pro tem, says she suggested to Pisano last year that the organization needed fresh blood, and that he could earn top coin as a consultant. He responded, in a conversation Young depicted as “calm and quiet,” that the money was unimportant, but she says she convinced him to retire.

“Enough is enough!” Young says. “Yvonne and me talked and we agreed he has been there a long, long time…. We have some serious problems. It’s not that Mark can’t fix them, but maybe somebody else will have newer ideas.” Pisano, reportedly still resisting, told Young that he’d hit the bricks next December.

SCAG is the largest urban-planning organization in the United States, employing 118 people on a roughly $35 million budget. Though wags have written it off as a “paper tiger” that knocks out reports nobody reads, Pisano’s troops have achieved some of their goals. SCAG championed the Alameda Corridor, a $2.4 billion expressway dedicated to freight traffic, which runs from L.A. and Long Beach harbors to downtown — although the relief SCAG promised from truck traffic on the nearby 710 and 110 freeways is still to materialize.

SCAG also persuaded cities to accept 700,000 new housing units by 2014, a controversial policy requiring that low-rise Los Angeles start building vertically — citywide.

Many of SCAG’s recent headlines were of a more embarrassing variety. Five years ago, Caltrans designated SCAG a “high-risk” recipient of government funds. While it worked for a disciplined approach against sprawl and pollution, SCAG bounced checks, comingled accounts and initiated an ill-conceived software project.

A flustered Pisano denied the flaws were as serious as Caltrans alleged. Still, that “high-risk” tag was the first ever placed on a council-of-government group in California history.

In 2005, Caltrans again red-flagged SCAG’s management, over a $947,000 contract involving Inland Empire traffic relief on State Route 71. The feds, citing the contract’s poor backup and language, docked California for the money.

Pisano, a Georgetown graduate and former federal Environmental Protection Agency division chief, has cut a natty groove. Lasting into the BlackBerry age, he remains erudite, prone to jargon-laced soliloquies, and in retention of phenomenal survival skills. When his wife, Jane, was a senior vice president at USC during the 1990s, they were one of L.A.’s hoariest power couples.

But in its 2006 report card, SCAG portrayed the L.A. area as a flunking giant. Mobility earned an F, air quality a C, and housing a D. As the purported coordinator of that regionwide planning, SCAG took the hits.

With an eye to SCAG’s limitations, Burke says a new joint-powers authority may be created to synchronize plans to reduce smog emissions by ports, trucks, airports and others without harming L.A.’s strength as a global shipping crossroads.

Where does Pisano fit in? Young acknowledges that SCAG has credibility problems.

“Mark is more a visionary than a planner. He got into a lot of trouble with his inability to manage,” Young says. “I told him, ‘You’ve done a lot. Maybe it’s time to bask in the glory.’ With all these years, it’s the Southern California Association of Mark Pisano.”