CHICAGO (CBS) — If you plan to hit the lakefront for a run or a bike ride, you might face a detour; a large section of the Lakefront Trail was closing Monday for the start of a major redevelopment project.

Beginning Monday morning, the trail will be closed between North Avenue and Diversey Parkway, as crews begin work to create separate paths for joggers and cyclists.

In order to accommodate construction, users of that section of the path will be detoured west of Lake Shore Drive, through Lincoln Park.

When completed, the new asphalt bike path will be 12 feet wide, and the new running path will be 20 feet wide, with 14 feet of asphalt and 6 feet of soft surface mix. The trail for runners will be closer to the lake, while they cycling path will be closer to Lake Shore Drive.

Officials said the goal is to make the trail safer for everyone, by making sure cyclists and runners aren’t exercising in such close proximity as they now do on the narrower current paths on the trail.

Beth Lakier said she’s had some close calls while using the trail, narrowly avoiding what could have been violent collisions.

“Especially on the bike, that’s for sure,” she said.

The construction work has been bankrolled in part by the richest man in Illinois, billionaire hedge fund manager Ken Griffin, who contributed $12 million for the project.

Alana Banai, with the Chicago Area Runners Association, said being temporarily detoured in the summer will be worth it in the end.

“Collisions are a big deal around here, and we stress safety with our training groups, so we’re really excited about this happeneing,” she said.

Similar construction later will take place between Oak and Ohio streets.

Separating runners and cyclists should help alleviate congestion in what is one of the busiest stretches of the trail.

The city plans to eventually create separate running and biking paths along the entire 18-mile trail. Work already has been completed on separate paths between 35th and 41st Streets. Plans are underway for 41st to 51st Street, starting later this summer.

The full project should be completed in 2018.