Unlike President Bush, Barack Obama is going to enter office with a clear appreciation of the urgent problems of climate change and America’s growing dependency on foreign oil  and a strong commitment to address both.

One way he can do this is to give mass transit  trains, buses, commuter rails  the priority it deserves and the full financial and technological help it needs and has long been denied.

Mass transit has always played second fiddle to the automobile, so Mr. Obama will need strong allies. Ray LaHood, Mr. Obama’s choice for transportation secretary, must be not only an ally but a champion for mass transit. Mr. LaHood is a Republican and former member of Congress from rural Illinois, where farmers produce a lot of ethanol and where people mostly drive. His résumé on transportation issues is thin, and we fear he may need some coaxing in this new direction.

Another important ally should be  and almost certainly will be  James Oberstar, a Minnesota Democrat who is chairman of the House Transportation and Infrastructure Committee.