The New Year will bring Arlington an exit of the articulate Chris Zimmerman after 18 years on the County Board. He’s satisfied and relieved, he tells me.

So are his opponents.

Zimmerman, an economist who chaired the board four times, will become vice president of economic development for the nonprofit Smart Growth America. “The 18 years was longer than I anticipated,” he says, “but I’m very proud of things we’ve been able to accomplish, with help from a lot of people. I didn’t want it to be my only career; I didn’t want to do politics my whole life.”

The new daytime opportunity will allow Zimmerman to “take some of the things we’ve done in Arlington to other places using the experience I’ve gained,” he continues, invoking the familiar goal of sustainability “that reflects such qualities as walkability and environmental, health, and social benefits.”

Riding sidecar in this transit-oriented vision, says Zimmerman – famous for navigating the county on foot – are lower crime and neighborhoods where residents know each other, as well as “Arlington’s values of diversity.”

As a top accomplishment, Zimmerman singles out the ART bus system –annual ridership grew from 1.2 million trips in 2008 to more than 2.6 million in 2013, the county reports. He’s also proud of the affordable housing ordinance and the Columbia Pike Transit Initiative.

The pike project includes, of course, the hotly disputed plan for a streetcar. That issue – coupled with past board spending on the Rosslyn Artisphere and the world-class Long Bridge Aquatic Center – has roiled Arlington’s electoral politics in recent years, and could tip the March special election for Zimmerman’s successor.

I get scathing emails called “growls” from Tim Wise, president of the Arlington County Taxpayers Association, and homebuilder Terry Showman blasting the board for the projects’ rising price tags and attitudes “beyond caring what people think” about whether projects remain viable.

Longtime Democrat Peter Rousselot, founder of Arlingtonians for Sensible Transit, lambastes the streetcar’s estimated costs that have “mushroomed from $120 million to at least $310 million and perhaps as high as $400 million.”

Though praising Zimmerman’s hours of service and expertise in smart growth, attorney Rousselot favors “a balance of change and continuity,” he told me. “The long-term incumbencies of Zimmerman and other board members has stifled innovation and fresh thinking. … We need leaders –regardless of political affiliation – who will re-direct budget priorities back to spending on core government services like schools, public safety, and maintenance of existing infrastructure.”

Zimmerman rejects the suggestion of a new anti-spending backlash. “You’re describing a political division that has always existed, that was waged 15 – 20 years ago by people who feel government shouldn’t do much,” he says. “Even though our taxes are lower than anybody else’s, some feel they can never be low enough.” Arlington’s success at growing the economy, he adds, “drives them crazy. They used to call us the People’s Republic of Arlington, but we’re also Virginia’s center of capitalism.”

Zimmerman’s only regret, he says, was temporary. After months representing Arlington at the Northern Virginia Transportation Authority in 2007, he’d all but given up when Gov. Bob McDonnell came forward this year to push the funding through, and suddenly “all that work was worth it.”

The streetcar, the board says, is now funded and proceeding. But Zimmerman will be occupied rediscovering “this thing called the weekend.”