In a move that will advance a project decades in the making, Transportation Secretary Ray LaHood today awarded a $25 million federal grant to a light rail system in downtown Detroit.

An additional $6.5 million will go to a rapid bus transportation system in the city.

"Detroit is the only large region in the country that doesn't have a regional transportation authority," LaHood said today during the U.S. Conference of Mayors in Washington, D.C. "When they asked us to fund the light rail, one of our stipulations was for the people and region of Detroit [to implement one]. They deserve a regional transportation authority, [and their] Legislature passed a bill establishing that."

LaHood said the system will help people get around to find better jobs, education and medical care as well as save money on gas.

Detroit's M-1 light rail project is a culmination of 40 years of effort. The $140 million project will bring a 3-mile streetcar line with 11 stations to the city's downtown area.

The grant was awarded through the Department of Transportation's TIGER program, which has doled out billions of dollars since 2009 for projects not funded under regular legislation.

LaHood praised Detroit's local government for its efforts securing the grant. And he encouraged the other mayors to apply for funding through a DOT program that provides low-interest loans for construction and infrastructure projects. He also urged the mayors to ask Congress for more funding for transportation programs.

"I think we need your help over the next two years. Congress is going to debate a transportation bill," LaHood said. "The debate is not going to be about what you need in your communities. ... The debate is going to be about how do we pay to be No. 1 again in infrastructure in America?"

What's next for LaHood?

LaHood today remained mum about whether he plans to stay on as Transportation secretary for President Obama's second term.

The former congressman initially agreed to take the position through Obama's first term, and there has been a flurry of speculation over when he will step down.

But LaHood would not discuss his plans when asked today.

It's been rumored that LaHood could be replaced by Los Angeles Mayor Antonio Villaraigosa or former Pennsylvania Gov. Ed Rendell (D). Women whose names have been mentioned for the post include New York City Transportation Department Commissioner Janette Sadik-Khan, DOT Undersecretary Polly Ellen Trottenberg and former Washington Gov. Christine Gregoire (D). Gregoire is also likely under consideration for the Interior secretary and U.S. EPA administrator openings.