By Colby Itkowitz, CQ Staff

The Transportation Department oversees the Federal Aviation Administration, which regulates civilian aviation and runs air traffic control; the Federal Highway Administration, which regulates road safety and delivers construction aid to states and cities; the National Highway Traffic Safety Administration, which regulates car safety; the Federal Transit Administration, which regulates and delivers aid for mass transit; the Maritime Administration, which promotes the merchant marine; the Pipeline and Hazardous Materials Safety Administration; and the Federal Railroad Administration.

For McCain

Mary E. Peters , current secretary

There is growing speculation McCain would ask his fellow Arizonan to stay on at least through the first half of next year, after which she wants to return to Phoenix to start her 2010 campaign for governor. In the Cabinet only two years, she appears to want more time to push her ideas, which include replacing the federal gasoline tax with a tax on drivers based either on how far they go or when they’re on the road. She has inserted herself in the early stages of the debate on the next highway bill, even though the current law is not up for renewal until 2010. A former Arizona transportation chief with a well-known fondness for motorcycles, she has developed good relations with both parties on Capitol Hill and with transportation advocates since arriving in Washington in 2001 to run the Federal Highway Administration.

Bill Graves, president of the American Trucking Associations

Part of a family that has been in the trucking business for seven decades, he took over the trade association in 2003 as soon as his eight years as governor of Kansas ended. He has led the campaign against the leasing of public roads to toll-collecting investors. One of his signature accomplishments in Topeka was a 10-year, $13 billion transportation program that included improvements for highways, railroads, airports and public transit service in the state — the sort of comprehensive approach that the next Transportation secretary will need in molding new surface transportation and aviation programs. But he demurred the last time the job was open, when Norman Y. Mineta retired in 2006.

Pete K. Rahn, Missouri Department of Transportation director

Rahn had been Transportation secretary in New Mexico when he was selected to help Missouri solve its infrastructure problems four years ago, namely fixing roads that at the time were ranked among the poorest in the industrialized world. During his time in Jefferson City, he has been hailed for having the sort of multi-tasking management skills that would be essential in running a federal transportation bureaucracy. He is also about to end his one-year term as president of the American Association of State Highway and Transportation Officials, which has afforded him a platform for developing relationships both in Congress and in the Bush administration.

For Obama

Edward G. Rendell , Pennsylvania governor

Now a publicly enthusiastic Obama backer after throwing ample political capital into Sen. Hillary Rodham Clinton ’s candidacy, Rendell recently told a Pennsylvania television station that he’d love to be Transportation secretary — but not until after his second and final term as governor ends in two years. In Harrisburg, and before that during eight years as mayor Philadelphia, he has been a forceful advocate for big increases in federal infrastructure spending. Along with GOP Gov. Arnold Schwarzenegger of California and independent Mayor Michael Bloomberg of New York, he recently formed a coalition, Building America’s Future, to press the case for big boosts in federal road and bridge spending. He would bring an unusual amount of political “start power” to the job.

Jane F. Garvey, executive vice president, APCO Worldwide

Before taking over the transportation portfolio at the lobbying and public relations behemoth five years ago, she spent Bill Clinton’s second term as the first woman to be the administrator of the Federal Aviation Administration. Early in Clinton’s first term, she moved from Boston where she ran Logan Airport and was the commissioner of the state’s Department of Public Works, to be deputy and later acting administrator of the Federal Highway Administration. Her experience running two of the department’s biggest agencies, both of which face congressional reauthorization in the next two years, would make her a viable choice for a president not deeply versed in transportation policy.