In-N-Out Burger is in.

In a surprise unanimous vote, Santa Rosa's Planning Commission Thursday agreed to let the popular fast-food burger chain locate a restaurant on Steele Lane Drive, despite worries that it would add to traffic congestion, would contribute to greenhouse gas emissions from idling cars, and promote obesity in neighborhood children.

Decisive support was won from Commissioner Nick Caston, part of the environmentally leaning majority, who said In-N-Out agreed to make the restaurant more pedestrian accessible and would encourage motorists stuck in the drive-up window waiting line to turn off their engines to reduce emissions.

Approval of the 3,350-square-foot restaurant, to be located on the northwest corner of Steele Lane and County Center Drive, was never in question. Under city zoning it was allowed on the 1.1-acre parcel that houses the former Lyon's Restaurant.

But In-N-Out needed city approval both to operate the drive-up window and extend its operating hours to 1 a.m. during the week and 1:30 a.m. on weekends.

Clean air advocates had marshalled forces to oppose the 232-store chain's use of drive-through windows, arguing it was a major producer of greenhouse gases because of the lines of motorists waiting for their orders.

Others said Steele Lane and County Center Drive, which feeds vehicles into the county's administrative complex to the north and Highway 101 to the west, already are congested.

Some even said allowing the fast food restaurant near schools, including Steele Lane Elementary, was encouraging obesity in young children.

Laurel Chambers, part of a nutrition coalition, said "a hamburger, fries and a milkshake" total 1,450 calories, nearly the full-time daily calorie requirement for an elementary-age student. "Consider the health of Sonoma County children," she said.

But In-N-Out supporters said denying the drive-thru would simply force people to waste more gas to drive to the nearest In-N-Out in Rohnert Park.

Brian Vogel took aim at those who blamed In-N-Out for childhood obesity:

"I can't believe we are blaming In-N-Out with making kids fat. You may as well blame spoons," he said.

City Traffic Engineer Jason Nutt said a new million-dollar, computer-controlled traffic light system expected to be installed along Steele Lane within the next few months should reduce congestion by around 10 percent, perhaps even more.

In-N-Out's most creative support came from Sonoma State University student Evelyn Baltazar who put the issue on a Facebook site and collected the names of 250 supporters in just a week.

The commission's decision is final unless it is appealed to the City Council within 10 working days. In-N-Out officials said they hope to have the restaurant open in late 2010.