Restaurant managers told the Friends they were unaware the boulevard, where the restaurant is located, would be off-limits to cars the day of the event, said Anton Vetterlein, Friends of Terwilliger vice president. Vetterlein said his organization contacted the restaurant in January and sent a letter in March about the event.

The Friends and restaurant managers discussed allowing cars on a quarter-mile stretch of Terwilliger, from Southwest Westwood Drive to Capitol Highway, the area that includes Chart House. Sunday Parkways participants would be rerouted down Capitol.

Vetterlein met with Chart House representatives and struck a compromise. The
Friends board will decide Thursday whether to accept the change.

Local Chart House managers wouldn't comment, but Peter Wagle, regional vice president for Chart House parent company Landry's Restaurants, said in a prepared statement that Chart House is enthusiastic about Sunday Parkways.

"The restaurant will set up a tent in the parking lot on Sunday from 11 a.m. to 4 p.m. and will distribute water and snacks to the participants," Wagle said. "We hope some participants will consider joining us for brunch or dinner during or after the event to watch fellow community members take part in the Sunday Parkways initiative."

To celebrate the 100th anniversary of the opening of Terwilliger, the Friends organized a three-day centennial festival that coincides with the Sunday Parkways event on July 22. The Friends added the Terwilliger extension to the main Sunday Parkways route.

Portland Sunday Parkways is a Portland Bureau of Transportation program begun in 2008 during which the city closes roads to motor vehicles in a certain area, allowing pedestrians to take to the streets: bicyclists, walkers, skaters, skateboarders, people in wheelchairs, joggers. The program's goals include increasing economic opportunities for local businesses, encouraging Portlanders to exercise and reducing their dependence on cars.

The upcoming event wasn't in danger of being canceled, but Anderson said he wasn't surprised an issue arose. He said Southwest has "posed unique challenges" because roads are not in a grid. Most events are held on a street paralleling a major road; Southwest's streets often don't connect or are on hilly terrain, requiring closing larger roads.

"We're not usually on major roads, and if we are, there's (alternative routes), but like you can in see in Southwest, there's not really an alternative to Terwilliger except Barbur," Anderson said. "There's not an alternative to Terwilliger in this case because it's celebrating the centennial."

Plus, he said event organizers prefer not to have an event on Barbur Boulevard, a state highway.

The Southwest event is the third of five this year, with the last in September. The 7.8-mile route wends though Hillsdale and Multnomah business districts, with activities, music, food and vendors on hand at Gabriel Park, Multnomah Village and Hillsdale Business District.

More than 107,000 people participated in the five events throughout the city last year. The Sunday Parkways budget is $474,000: $253,000 from sponsorships, $29,000 from vendor fees, $22,000 from donors and $170,000 from the Bureau of Transportation, Anderson said.

"When Sunday Parkways comes to a neighborhood for the first time," he said, "the first request we get from people when it's over is: Please bring it back next year."