Idling Facts

Idling is money

out the tailpipe

Think about it - an idling vehicle

actually gets negative MPG

Idling is bad for

air quality and health

Idling emissions can cause cancer and

cause or exacerbate asthma

Idling contributes to

climate change

In California, parked idling annually

emits three million tons of CO2*

Idling wastes energy

In California, parked idling annually

burns 300 million gallons of fuel*

Idle Reduction Technologies for vehicle fleets from NACFE (North American Council for Freight Efficiency)

Idling can be necessary

In weather extremes adequate defrosting and health of occupants

may necessitate idling; visit this site

on desktop computer for details




• The U.S. Dept. of Transportation - Office of Highway Policy Information - Motor Fuel Use - 2018: U.S. fuel consumption 180,737,076,000 gallons

• The U.S. Dept. of Energy originally stated in 2012 and maintains today: "Each year, U.S. passenger cars, light-duty trucks, medium-duty trucks, and heavy-duty vehicles consume more than 6 billion gallons of diesel fuel and gasoline—without even moving. Roughly half of that fuel is wasted by passenger vehicles."



•The U.S. Dept. of Transportation - Office of Highway Policy Information - Motor Fuel Use - 2018 - California fuel consumption 18,010,964,000 gallons

• Factor that decreases idling in California since 2012 U.S. DOE statement: as of the 3rd quarter of 2019, 7.9% of all vehicles in California are plug-in hybrid and electric. Additionally, hybrid sales are higher in CA than the rest of the country; this represents an approximately 10% idling decease in CA than nationally

• Factors that increase idling in California (and elsewhere) since 2012 U.S. DOE statement: nearly 5% increase in vehicle fuel use statewide; in-vehicle behaviors such as use of devices like smartphones; door-to-door delivery and ride-hailing services

• Putting this all together (in lieu of no far ranging studies on vehicle idling in California), based on U.S. overall transportation fuel consumption vs U.S. vehicle idling fuel consumption, it is estimated that all vehicles in California consume approximately 600 million gallons of fuel when idling annually. This results in six million tons of CO2 emitted by all idling vehicles in the state. This equates to idling in California being approximately 10% of idling nationally.


Studies show that about one-half of all idling occurs when parked (not in traffic).1, 2. Therefore, it is estimated all vehicles idling when parked in California consume 300 million gallons of fuel, resulting in three million tons of CO2 emissions. MOST OF THIS IDLING IS CONSIDERED UNNECESSARY.


1Vanderbilt University study: Costly myths: An analysis of idling beliefs and behavior in personal motor vehicles (p.4). "...the average American idles for roughly 16 min a day. Over 51%...can be accounted for by individuals idling while in traffic...the remaining 49%...results from idling to warm and while waiting, both of which are avoidable and, in many cases, unnecessary."

2University of Vermont study: Passenger vehicle idling in Vermont (p.25): "Discretionary idling is a large enough percent of all idling in Vermont (approximately half) to suggest policies to pursue behavior change over purely vehicle technologies which eliminate all idling emissions by turning off during travel and at stops."


Other Idle Free Efforts


Spare the Air: Turn the Key – Be Idle

Free! San Francisco Bay Area

• - Oceanside:


Idle Free Bay Area (Spare the Air)

Idle Free Oakland

Grades of Green - No Idle Zone Los

Angeles South Bay area

• U.S. Dept. of Energy Clean Cities

coalitions: California has 13 Clean

Cities implementing various degrees

of idle reduction initiatives, as well as

Clean Cities in other states. In general,

Clean Cities offers their IdleBox

Toolkit for idling reduction projects.



Keep it Clean. Be Idle Free. Washoe

County, NV

Utah Clean Cities, Being Idle Free is


Engines Off!, Denver CO

Kentuckiana Air Education (KAIRE) Idle

Free, Louisville, KY

IdleFreePhilly, Philadelphia, PA (and


Idle Free for Our Kids eLearning,

Halifax, Nova Scotia

• U.S. national: It's Your Turn - Turn It Off Sustainable America

• U.S. Dept. of Energy: Idling Reduction

for Personal Vehicles - EXCELLENT


• U.S. Dept. of Energy Clean Cities:

IdleBox Toolkit for Idling Reduction


U.S. EPA Idle Free Schools for a Healthy School Environment



Idle-Free Tips

Idle-Free Handouts

What You Can Do