Incentive and Law Additions by Fuel/Technology Type

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Aftermarket Conversions [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] 9 17 14 7 6 1
Biodiesel 28 35 25 37 74 97 59 57 43 39 16 43 16 20 9 6
Blends 6 8 9 18 30 51 26 [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object]
Efficiency 0 6 4 6 9 8 13 18 9 9 8 7 4 10 1 1
Emissions 6 8 12 4 23 16 16 [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object] [object Object]
Ethanol 25 29 17 30 70 98 65 52 44 42 13 42 12 21 9 4
Electric Vehicles 24 34 21 26 40 32 28 50 51 64 49 48 46 65 41 50
Hybrid Electric Vehicles 4 8 10 15 19 18 24 33 33 47 38 42 14 15 6 5
Hydrogen 22 24 18 18 44 28 23 34 24 20 13 25 13 17 13 16
Idle Reduction 0 2 4 16 18 10 20 23 9 9 3 12 8 8 4 1
Natural Gas 28 38 16 23 45 32 27 40 43 34 38 57 50 41 22 15
Propane 27 27 14 21 30 27 22 33 20 25 18 31 31 29 14 8
Neighborhood EVs 0 0 0 0 0 0 0 0 0 0 0 0 3 0 1 0
Other 12 16 21 22 53 67 42 11 16 6 9 15 7 14 6 19
Source: National Renewable Energy Laboratory
Notes: Additions mean any incentive or law that was added to the AFDC, which is usually the same year that it was enacted or brought into force. This count includes legislation that has since expired.

Because a regulation may apply to more than one technology type, adding the totals for each row results in counting some regulations multiple times.

Aftermarket conversions were not tracked in their own category until 2012.

The electric vehicles category includes both electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs).

Neighborhood EVs were not tracked in their own category until 2014.

After 2008, the emissions category was moved to the "other" category, and the blends category was moved to the ethanol or biodiesel categories.

This chart shows trends in incentives and laws related to alternative fuels and advanced vehicles, enacted in all 50 states and the District of Columbia from 2002 to 2017. Visit the Incentives and Laws page for information on federal and state incentives and laws.