A groundbreaking next month for a $25 million project that will rebuild the intersection of Hwy. 7 and Louisiana Avenue in St. Louis Park is expected to improve safety and traffic flow along one of the suburb's few north-south corridors.

City officials also hope that a new grade-separated traffic crossing will help spur redevelopment and fill empty office space in an area once dominated by some of the most heavily polluted industrial sites in the Twin Cities metro.

The Louisiana Avenue corridor is an important one in a city that has plenty of east-west routes, including Hwy. 7, but few north-to-south corridors. The at-grade intersection with stoplights has long been a problem area for cars and people along Louisiana. Cars are often caught in a bottleneck because of the long traffic light, and pedestrians have to brave a wide highway crossing.

Planned improvements seek to fix that. A new overpass will carry Hwy. 7 over Louisiana Avenue, eliminating the stoplight. Diamond-type entrance and exit ramps will connect them.

A revamped Louisiana Avenue, meanwhile, will include three new roundabouts that will route traffic on and off the highway, and through rebuilt intersections with two frontage roads, including Walker Street to the north and W. Lake Street to the south.

By the time it's completed in June 2015, the rebuilt Louisiana Avenue will feature upgraded paths for pedestrians and bikes, creating a safer, more walkable connection between the two sides of the highway.

Ultimately, if the proposed Southwest Corridor light-rail transit line is built, a station is slated to be built along Louisiana Avenue south of the interchange near Methodist Hospital.

Walker and Lake Streets have already seen some redevelopment activity since the days when they fronted a pair of notoriously contaminated sites, said Greg Hunt, St. Louis Park's economic development coordinator.

That included the former Reilly Tar & Chemical Co. The 80-acre Superfund site was used to produce creosote, mainly used to coat railroad ties, from 1917 to 1972.

Anderson Builders, which has been based in St. Louis Park since 1999, built the Oak Hill office building within the Superfund area. In 2008, the company acquired a nearby site at 3340 Republic Avenue.

Anderson, which merged with KM Building Co. last year, proposed building a 21,432-square-foot facility called Oak Hill II that would house a new headquarters for the merged development firm, now known as Anderson-KM Builders.

Late during the last decade, Real Estate Recycling transformed the contaminated site of a former lead smelting operation along W. Lake Street into the Highway 7 Corporate Center.

Hunt said the city also hopes the new interchange will help generate interest in a city-owned surface parking lot in the southwest quadrant of the intersection.

"We're looking at that as a potential spot for a new office building," he said.

The new interchange "can only help" the commercial real estate potential of the area, said Jason Simek, a broker for Colliers International, which is seeking a buyer or medical tenant for the vacant 4,000-square-foot Highway 7 Office Center at 7104 W. Lake St.

With 45,000 cars per day traveling Hwy. 7, the area already has high visibility and is within easy reach of retail, hotels and restaurants.

"It will certainly improve access to West Lake Street," Simek said.

The downside of the project is two years of construction-related traffic delays at the intersection, which worried a coalition of local business owners who have questioned the need for the project.

In December, the group negotiated with the city and was able to forge a new construction staging schedule that will keep four lanes of Hwy. 7 and Louisiana open with no detours during the first year.

Don Jacobson is a freelance writer in St. Paul.