It's official -- the first-ever downtown Minneapolis "railgating" party is on.

City officials and representatives of the Minnesota Vikings signed off Tuesday on a plan to allow more than a dozen food vendors to set up shop along a two-block stretch of the Hiawatha light-rail line Sunday in hopes of luring more fans -- especially those commuting by rail -- downtown before the team's noon kickoff with the San Francisco 49ers at the Metrodome.

The experiment, dubbed railgating, is designed to "add more sizzle" to pre- and postgame festivities, Minneapolis Mayor R.T. Rybak said Tuesday.

"We're encouraging people to come downtown and be part of the street life and come in and watch the game or have fun in a bar and restaurant instead of watching it in their living room," he said.

More details of the plan will be discussed at a 9 a.m. Wednesday briefing on 5th Street, across from the Minneapolis Armory.

The railgating idea is part of a broader vision by Rybak and city officials to provide fans with an alternative to more traditional tailgating, and generate more game-day traffic and activity in advance of the opening of a new downtown stadium in 2016.

The $975 million stadium will be built on and near the Metrodome site, which is set in one of the most urban settings in the NFL. Because of its location, the site -- compared with other NFL venues -- provides relatively few parking spaces where fans can grill, party and toss a football before and after games.

Rybak said he hopes the city and downtown restaurateurs can eventually turn Fifth Street -- from the Warehouse District on the west side east to the Metrodome -- into a "Purple Path," where fans gather at food and beverage trucks and celebrate at the nearby Armory or a public plaza before and after games.

"The top point here is we want to paint the town purple," Rybak said. "We want people to come to the game but spend time here before and after."

"It makes a lot of sense," said Lester Bagley, Vikings vice president. "It's a little bit of an experiment and we'll see how it shakes out. But anything that enhances the game-day experience and brings more people down to the stadium early is a good thing."

For Sunday's game, the city will close a single lane of traffic along two blocks of 5th Street running from Park to 5th avenues, just west of the Metrodome. Food trucks will set up in the street between the light-rail line and the sidewalk, blocking off the rail line, which will continue to operate.

Vendors will set up at 7 a.m. and stay open to 1 p.m., an hour past the opening kickoff.

Initial plans for a beer vendor peddling Minneapolis brews fell through, but Rybak said that idea may be revived.

City officials also plan to open up some curbside parking Sunday for more traditional tailgating by fans who drive to the game. Rybak said the idea is to pull tailgaters out of the more residential Mill District and Elliott Park neighborhood and into downtown, where "you can be loud and have fun in the office core."

The railgating idea is the first of several the city plans to initiate and fine-tune in advance of the opening of the new stadium.

"We're going to take it one week at a time," Rybak said.

Richard Meryhew • 612-673-4425