In Vermont, motor vehicles are the largest source of greenhouse gases and a number of other air pollutants that threaten human health and our environment. Unnecessary idling harms human health, pollutes the air, wastes fuel and money, and causes excess engine wear. And it’s against the law.
We estimate that if every car and truck in Vermont reduced unnecessary idling by just one minute per day, over the course of a year Vermonters would save over 1 million gallons of fuel and over $2 million in fuel costs, and we would reduce CO2 emissions by more than 10,000 metric tons.
While individual actions may be small, the cumulative impacts of idling are large.
Health and Environmental Impacts
Exhaust from idling vehicles includes:
- Greenhouse gases, which contribute to climate change;
- Volatile organic compounds (VOCs) and nitrogen oxides (NOx), which combine to form ground level ozone that triggers asthma attacks, damages lung tissue, and damages forests and crops;
- Fine particulate matter (PM), which causes respiratory and cardiovascular damage, and leads to haze that limits visibility;
- Sulfur dioxide (SO2) aggravates lung disease and other breathing problems;
- Toxic and carcinogenic compounds such as benzene, aldehydes and butadiene; and
- Carbon monoxide (CO), which interferes with the delivery of oxygen to the body’s organs and tissues.
Toxic and carcinogenic air pollutants are of concern because they are known or suspected of causing cancer in humans, and pose a threat even at very low levels. Diseases aggravated by air pollution include chronic sinusitis, bronchitis, asthma, and allergies. Studies show that air pollution poses significant risk of pulmonary problems in developing fetuses, young children, and older individuals, and damages the immune system in healthy adults. Several compounds in gasoline are toxic and known carcinogens and the World Health Organization has determined that diesel exhaust causes cancer in humans.
Vehicle exhaust contributes to acid rain, which forms when pollutants emitted into the atmosphere dissolve in cloud droplets. Acid rain affects the chemistry and biology of lakes, streams, forests, and other ecosystems. For example acidification of our lakes and streams can reduce fish populations.
Vehicle exhaust contributes to global climate change. Vermont’s native fish, wildlife and plants are vulnerable to climate-related changes. Vermont is rich in natural resources which support many local businesses such as maple sugar producers; provide residents and visitors with winter sports opportunities; and create the green mountains of our summers and vibrant colors for which our autumns are famous.
The Costs of Idling
- Idling is the literal equivalent of 0 miles per gallon.
- According to the US Department of Energy (DOE), idling in the United States uses more than 6 billion gallons of fuel at a cost of more than $20 billion each year.
- Fuel is only partially combusted when idling because an engine does not operate at its ideal temperature. This leads to the buildup of fuel residues on cylinder walls that can damage engine components and increase fuel consumption.
- Letting an engine idle actually does more damage to the engine than starting and stopping. Running an engine at low speed (idling) causes more wear on internal parts compared to driving at regular speeds, which can increase maintenance costs and shorten the life of the engine.
- Excessive idling often decreases the lifespan of engine oil, leading to unexpected engine problems.
- Current passenger vehicle owner’s manuals contain information on how to get the best and most economical performance and often recommend avoiding idling.
- Manufacturers of heavy-duty engines and trucks, including Kenworth Truck Company, Caterpillar, IC Corporation and Cummins Inc. advise operators to limit idling to a maximum of 3-5 minutes.
- Motor Vehicle Idling Law (V.S.A. Title 23 Chapter 013 Section 01110). Act 57 was signed into law in May 2013 and includes a provision that, effective May 1, 2014, limits all motor vehicle idling to five minutes in any 60 minute period with some exceptions.
- School Bus Idling Rule on School Property. School buses shall not idle while picking up and dropping off children on school property.
- Idle-Free VT, Inc. – a non-profit organization raising awareness of unnecessary idling.
- Vermont Idle Free Fleets – a free online training developed in partnership with the American Lung Association of the Northeast and the Certification for Sustainable Transportation at the University of Vermont for Vermont diesel truck and bus drivers and fleet managers about the benefits of idle reduction.
- Vermont Clean Cities Coalition – a non-profit organization promoting alternative fuels and energy independence and provides a toolkit for idle reduction projects.
- Argonne National Laboratory – a multidisciplinary science and engineering research center providing idle reduction tools, idling publications, and details about idle reduction research.
- Factsheet – Idle Reduction for Personal Vehicles, a PDF file
- Factsheet – Emission Facts, a PDF file