Just saw this and felt like you might be interested.

NYC has just begun testing a new bus. It has an all electric power train, with a small gas turbine powered generator supplying the charge along with regenerative braking. Seems like a similar system to the Volt.

An advantage is that because of how efficiently the turbine runs, the exhaust is cleaner than a standard diesel bus without the need for any exhaust gas treatment.

Very cool.

M.T.A. Tests Sleeker Bus With Turbine Engine - City Room Blog - NYTimes.com

[ame=http://en.wikipedia.org/wiki/DesignLine_International]DesignLine International - Wikipedia, the free encyclopedia[/ame]