Bus riders in Santa Rosa will have to navigate some new downtown terrain beginning Sunday, when the city's transit mall is relocated a block away for the summer.

City, county and regional buses for the next three months will pick up and drop off passengers along First Street just north of City Hall while construction crews give the aging Second Street mall a long-delayed facelift.

First Street was closed to traffic when the Tour of California came to town in May and has remained blocked off as workers transformed the area into a temporary transit mall.

Bright blue benches and garbage cans have been installed along the sidewalks. Banners tell riders where to catch their buses. Temporary bathrooms are now located in a nearby lot. And security cameras on light poles peer down on the activity below.

Buses will begin using the new area Sunday, a light-volume day for bus traffic, to give drivers and passengers a chance to get used to the new depot.

Crews will begin upgrades aimed at giving the 26-year-old transit mall a more user-friendly feel.

"We're going to be tearing out everything but the roadbed," said Jason Parrish, project manager.

The transit mall is sandwiched between the AT&T building and two vacant buildings to the north and the Roxy Stadium 14 theater and a city parking garage to the south.

Parrish hopes removing thick steel support structures and replacing them with arching light poles, local artwork and updated signs will give the mall a more open and inviting feel that should boost bus ridership.

"If people feel safe with a transit system, they are more likely to use it," Parrish said.

The transit mall opened in 1986, when the downtown stops for the various bus systems were relocated from Old Courthouse Square to Second Street between B Street and Santa Rosa Avenue.

The mall is now the North Bay hub for Santa Rosa city buses, Sonoma County Transit, Golden Gate Transit and Mendocino Transit Authority, drawing approximately 10,000 people daily.

The mall update dates back to 2006 when Santa Rosa had several proposed mid-rise residential buildings on the drawing board and officials figured they'd better spiff up the aging transit mall for all those new downtown denizens.

The housing bust has since burst that bubble, but the transit mall plans continued, winning the federal and regional grant funding dollars needed to pay for most of the $3.1 million project. Local transportation dollars provided the balance.

The upgrades were delayed two years ago because of the Museum on the Square redevelopment project, including a dispute over whether residents of the project proposed for the former AT&T building could drive through the transit mall to reach their parking spaces.

The work was pushed back again last year when staffing changes kept the city from hitting the summer construction window, when ridership drops by up to 20 percent when school is out, Parrish explained.

In March, the City Council awarded the $2.1 million construction contract to R.E. West Builders of Santa Rosa. The work is expected to get under way Monday and be complete by September.

The updated transit mall will include new lighting, sidewalks, color-coded signs and modern security cameras. It will also feature larger bus shelters and three large LED screens providing updated bus arrival and departure times, much like an airport.

"We want to get the latest, greatest technology in while we can," Parrish said.

Instead of the "San Quentin look" of the steel bars that separate the mall from the adjoining parking garage, Parrish said the spaces will be separated by metal sheets cut to create artistic images of roses, the city flower.

The Artstart program will also install a large mural of an oak tree on what is currently a blank wall, he said.

You can reach Staff Writer Kevin McCallum at 521-5207 or kevin.mccallum