"Light rail is not dead. It's back on the table," Bing told reporters outside his office at the Coleman A. Young Municipal Center.

After 90 days, a decision will be made -- it was not said by whom -- on whether the plan by M1 Rail would pass muster. If it does, the rail project would be merged with a plan for a high-speed regional bus system.

"This project is going to move ahead in a parallel process," Gov. Rick Snyder said.

A $528 million public-private plan to build nine miles of rail from downtown to the city limit at Eight Mile Road was scrapped in December for a $500 million, 110-mile system of speedy buses for the region. The system would be built and operated by federal funds and money generated for a proposed regional transit authority.

No other details about the plans were disclosed this afternoon.