Lured by a $100 million carrot, a Chicago civic group is ramping up its effort to revive plans for expanded transit service in the bustling and increasingly congested Loop area with a new element: better transit to the Barack Obama library site, too, combined with new investment in housing and jobs on the South Side.

The new proposal comes from the Chicago Central Area Committee, a 60-year-old organization focused on growing and making downtown work better. It's being disclosed now because CCAC is bidding for an innovative $100 million grant that Chicago-based MacArthur Foundation is offering for the best big idea worldwide. Those applications were due early this month, and the foundation is expected to release its short list of finalists soon.

Though CCAC's plan is expansive, even wild in its ambition, it puts together in one spot two obvious concerns: downtown's need for added capacity on Chicago Transit Authority lines from the north and west, which now are near capacity in peak hours, and the South Side's need for both new service and massive redevelopment help.

The catalyst is the Obama library, which would be at the east end of the Hyde Park neighborhood in Jackson Park, roughly between 60th and 63rd streets. Right now, the location has only occasional service nearby on Metra's lakefront Electric Line.

"Chicago today is two cities," says a CCAC video submitted as part of the MacArthur application. "One buzzing with life and attracting the world's best and brightest. . . .The other is in need of investment.”

A narrator in the video is Jacky Grimshaw, a major figure in the city's African-American political establishment who served as Mayor Harold Washington's intergovernmental relations chief and, until recently, was Obama's next-door neighbor in Kenwood. She's now vice president of policy at the Center for Neighborhood Technology.

"We need to expand our transit system. And we need to bring in people who have been left out," Grimshaw said in an interview. "It's a vision. I can't put a guarantee on it. But (Obama) could help get us where we need to go.”

READ THE REPORT: A PDF of the CCAC's proposal

Much of the idea comes from Ed Zotti, a transit consultant and researcher. I wrote a couple of years ago about how he was working with CCAC to try to revive the old Central Area Circulator or connector plan, starting with a transit line from Union Station to Streeterville, mostly using existing right-of-way under the Merchandise Mart, Trump Tower and Tribune Tower on the north bank of the river.

The new element calls for the creation of a Chicago Transit Redevelopment Trust.

The trust would help generate support, planning and some funding for both the riverbank line and new service along Metra right-of-way as far as 79th Street, either a new line run by the CTA or much more frequent Metra service.

The trust also would be authorized to buy and invest in property near transit lines. As development and land values grow, the property would be sold and proceeds invested in South Side developments, CCAC says.