DETROIT (AP) - If there's one weight slowing down the city's rising Super Bowl star, organizers say it is transportation.

Detroit is at the core of one of the largest metropolitan areas in the country without a comprehensive mass transit system, a weakness that showed itself during Super Bowl weekend, when suburbanites coming downtown for a winter festival overwhelmed a shuttle bus system.

"Everything was absolutely perfect, except the Park and Ride," Mayor Kwame Kilpatrick said at a post-Super Bowl news conference yesterday.

Outlying lots, particularly Saturday night at a Macomb County shopping mall, were filled to capacity, and there were reports of people waiting hours for buses headed downtown. More than 300,000 people used the shuttles Saturday alone, and Kilpatrick conceded that officials didn't expect such large crowds.

He said the region needs mass transit, adding that Detroit lost a professional bowling tour stop to Salt Lake City because it has a mass transit rail system.

Detroit operates a bus system within its boundaries, but it is separate from a three-county suburban system. There are no commuter rail lines, and numerous attempts at creating a regional transit system have failed.

Larry Alexander, president of the Detroit Metro Convention & Visitors Bureau, said mass transit is critically important to luring more Super Bowls and other large-scale events.

He said he would like to see rail service between downtown and Detroit Metropolitan Airport, about 20 miles away in Romulus.

"The missing link is this mass transportation," Alexander said.

Detroit's competitors for event business, such as Chicago and Washington, all have train systems in place, he said.

Frank Supovitz, the NFL's senior vice president of events, said the lack of rail service wouldn't hurt Detroit should it seek another Super Bowl because the city was able to move large numbers of people with buses last weekend. But rail service "is certainly helpful," he said.

Kilpatrick, a Democrat, said that during Super Bowl week, he brought Michigan House Speaker Craig DeRoche (R-Novi) downtown to see the festivities and talk about mass transit funding and other issues.

DeRoche said he and Kilpatrick agreed to work together on mass transit.

"While we don't have anything to announce immediately, I hope to be able to find solutions that work that we can both get behind," DeRoche said.

Last year, Congress allocated $100 million to the region to study rapid transit in a 50-mile corridor from Detroit west to the airport and Ann Arbor.

The Southeast Michigan Council of Governments, which is leading the study, has narrowed the field to five options: Two locomotive-powered commuter rail routes largely along existing railroad lines, two bus rapid-transit routes on high occupancy vehicle lanes, and one light rail trolley route, said Alex Bourgeau, the group's coordinator of intermodal transportation.

Railroad tracks already link the Amtrak stations in Ann Arbor and Detroit, but the Detroit station is north of downtown. The study includes ways to get trains to the heart of downtown, Bourgeau said.

Consultants are now calculating the capital and operating costs of each option and will present details to a steering committee in April.

Early cost estimates show that the options would run from just under $500 million to as high as $2 billion to build the entire system, Bourgeau said. Light rail trolleys would be the most expensive option, and commuter rail trains on existing tracks the least, he said.

To get the $100 million, the region would have to compete with other metro areas and would have to come up with at least $20 million in matching funds, Bourgeau said.

But if it got the money, at least part of the system could be designed and built. "We could do some significant portion of this, probably not all 50 miles," he said.

The matching money could be a problem, though. Detroit is facing a projected $40 million deficit in the current fiscal year, and the state has faced several years of tight budgets and spending cuts.

Since most transit systems can't run on fares alone, the region also would have to figure out how to pay operating costs, Bourgeau said.

"Certainly in this economic climate, going out and asking for more money is tough," he said.

DeRoche said any mass transit system probably would have to include more areas to gain the necessary legislative support, including Oakland and Macomb counties and west Michigan.

It could be funded, he said, by re-prioritizing the use of gasoline tax money.