In the United States, experts say 14 million people take public transportation each day. Today, there's a big push to make all of those engines run cleaner and burn fewer fossil fuels. Some experts say it's a problem capturing the attention of researchers across the country. They say they hope to meet transportation demands in a way that's more environmentally friendly. The Rochester Institute of Technology in New York state is on the cutting edge. It's created a new Sustainability Institute to look for answers. Nabil Nasr with the Golisano Institute says, "We are looking at different alternative fuels from biodiesel to ethanol to hydrogen as fuel cells. We are looking at all the alternative fuel options that we have and looking at when some of these options will be ready for broader use." Alternative fuels are already used in buses. But, some times change comes at a higher cost. Mark Aesch with the Rochester Transportation Authority says, "It used to cost almost double to buy a hybrid bus as opposed to a regular diesel bus, but we've seen those prices really drop back. Today a hybrid bus is only about 50% more." One way to cut down on emissions is to get more people to take public transportation in the first place. Experts say U.S. reliance on foreign oil would decrease 40% if one in ten Americans used public transportation daily. When considering public transportation, experts say you might also want to consider this: You're 79 times safer riding in a bus than driving your own car. Experts say a diesel powered school bus produces 6,000 pounds more pollution than a natural gas model.