We have a problem with the environment, we are running out of petroleum, and we have a problem with obesity in some parts of the world.
Public transit is good for the environment, if we use public transit it cuts down on the amount of cars on the road, and the amount of gas we use. What if we had electric or hybrid buses in our transit system? What if we harnessed solar energy?
Here's the energy I think we are forgetting: all those people riding the bus are just sitting there (including me). When you give people a chance to contribute, they will. I would. Being a leader in government could mean enabling the public to contribute (think "ask not what your country can do for you, but what you can do...."). What if the people riding the bus could do something to create energy (electricity) for the bus?
You know those flashlights you can take camping that charge up by turning a crank? What if we had things like that on the bus? Or even better, what if there were pedals, or something else? We could get a bit of exercise while we go to school or work or the mall or whatever. The electricity could be stored in batteries to run the bus (or to run some parts).
Since public transit is often subsidized (sp?) by the government, and the government is supposed to be taking initiative to promote a healthier (less obese) public, they could do something on the bus like this: if you generate a certain amount of watts, you get a ticket for a free bus ride. Or, you can donate your watts back to the bus, lowering the price of that bus (ie: standard fare is 2.75, enough people generate watts and donate them, and the price is 2.00 until the watts run out).
This gives people a chance to contribute to a healthier environment, plus get some exercise (if they choose to, they could still just ride), possibly get a free bus ride, or make the bus even more affordable for others.