EV subsidies, Electric and hybrid buses in the US.

Study tip: The International Council on Clean Transportation (ICCT) found that in U.S. states with the highest subsidies for EVs, the market share for electric vehicles was two to four times higher than the national average.
greencarcongress.com

Reading tip: This article gives an overview of what regions are planning for electric and/or hybrid buses and when these will go into service. In 2013, 13 percent of buses in the US were all-electric or hybrid.
eenews.net