Madison, Wis., will use $9.5 million in federal stimulus money to buy more diesel-electric hybrid buses, according to the Associated Press.

Madison Mayor Dave Cieslewicz says the city plans to buy 18 more of the buses, which cost $500,000 apiece. That amount is $180,000 more than a regular bus. The city bought its first five hybrid buses in 2007.

Cieslewicz says the hybrids will replace existing buses and help reduce emissions because they use 30 percent less diesel fuel than regular buses.