By Grace Austin

The Chicago Lakefront Trail runs for 18 miles along Lake Michigan, drawing in runners, dog walkers, beach goers, roller bladers and bicyclists. It passes marinas, beaches and public art that includes massive sculptures.

But congestion during the warmer months, especially between bike riders and joggers, has created an outcry for separate lanes. With a $12 million gift from Chicago billionaire Ken Griffin, new construction is beginning that will do just this.