Editing Commuting (section)

== Pollution ==
Cars carrying only one occupant use [[fuel]] and roads less efficiently than [[Carpool|shared cars]] or [[public transport]], and increase [[traffic congestion]].  Commuting by car is a major factor contributing to [[air pollution]]. Carpool lanes can help commuters reach their destinations more quickly, encourage people to socialize, and spend time together, while reducing air [[Air pollution|pollution]]. Some governments and employers have introduced employee travel reduction programs that encourage such alternatives as [[carpool]]ing and [[remote work]]. Some are also carpooling using Internet sites to save money. Alternatives like [[personal rapid transit]] have also been proposed to reap the energy-efficiency benefits of a mass transit system while maintaining the speed and convenience of individual transport.

Traffic emissions, such as from [[car]]s and [[truck]]s, also contribute.<ref>{{cite web |title=Clearing the Air |publisher=The Surface Transportation Policy Project |date=19 August 2003 |url=http://www.transact.org/report.asp?id=227 |access-date=2007-04-26 |url-status=dead |archive-url=https://web.archive.org/web/20070208230135/http://www.transact.org/report.asp?id=227 |archive-date=8 February 2007 }}</ref> Airborne [[by-product]]s from vehicle [[exhaust system]]s cause [[air pollution]] and are a major ingredient in the creation of [[smog]] in some large cities.<ref>{{cite press release | url = http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/228d9bf38da42f7c8525743b006db951!OpenDocument&Start=1&Count=5&Expand=1 | title = EPA Tools Available as Summer Smog Season Starts | date = 30 April 2008 | publisher = United States Environmental Protection Agency | location = Boston, Massachusetts}}</ref><ref>{{cite web | url = http://www.sierraclub.org/sprawl/report01/carsandtrucks.asp | title = Sprawl Report 2001: Measuring Vehicle Contribution to Smog | publisher = Sierra Club | year = 2001 | access-date = 15 January 2017 | archive-date = 15 November 2001 | archive-url = https://web.archive.org/web/20011115044348/http://www.sierraclub.org/sprawl/report01/carsandtrucks.asp | url-status = dead }}</ref><ref>{{cite web | url = http://library.thinkquest.org/26026/Environmental_Problems/smog_-_causes.html | title = Smog – Causes | work = The Environment: A Global Challenge | access-date = 25 October 2013 | archive-date = 19 January 2001 | archive-url = https://web.archive.org/web/20010119154200/http://library.thinkquest.org/26026/Environmental_Problems/smog_-_causes.html | url-status = dead }}</ref><ref>{{Cite journal | url = http://www.epa.gov/air/ozonepollution/pdfs/smog.pdf | publisher = United States Environmental Protection Agency | date = July 1999 | title = Smog – Who Does It Hurt? What You Need to Know About Ozone and Your Health (EPA-452/K-99-001) }}</ref> The major culprits from transportation sources are carbon monoxide (CO),<ref>{{cite web | url = http://www.epa.gov/cgi-bin/broker?_service=data&_debug=0&_program=dataprog.national_1.sas&polchoice=CO | work = Air Emission Sources | title = State and County Emission Summaries: Carbon Monoxide | date = 25 October 2013 | publisher = United States Environmental Protection Agency}}</ref><ref name="queensland">{{cite web | url = http://www.tmr.qld.gov.au/Community-and-environment/Environmental-management/How-you-can-make-a-difference/Motor-vehicle-pollution.aspx | title = Motor vehicle pollution | publisher = Queensland Government | date = 4 April 2013 | access-date = 15 January 2017 | archive-date = 5 December 2019 | archive-url = https://web.archive.org/web/20191205161028/https://www.tmr.qld.gov.au/Community-and-environment/Environmental-management/How-you-can-make-a-difference/Motor-vehicle-pollution.aspx | url-status = dead }}</ref> nitrogen oxides (NO and NO<sub>x</sub>),<ref name="epa-no2">{{cite web | url = http://www.epa.gov/air/nitrogenoxides/health.html | work = Nitrogen Dioxide | title = Health | publisher = United States Environmental Protection Agency | date = 14 February 2013}}</ref><ref>{{cite web | url = http://www.epa.gov/air/noxfacts.pdf | title = The Regional Transport of Ozone: New EPA Rulemaking on Nitrogen Oxide Emissions (EPA-456/F-98-006) | publisher = United States Environmental Protection Agency | date = September 1998}}</ref><ref name="EPA_NOx">{{cite web | url = http://www.epa.gov/cgi-bin/broker?_service=data&_debug=0&_program=dataprog.national_1.sas&polchoice=NOX | title = State and County Emission Summaries: Nitrogen Oxides | work = Air emission sources | publisher = United States Environmental Protection Agency | date = 25 October 2013}}</ref> [[volatile organic compound]]s,<ref name="queensland" /><ref name="epa-no2" /> sulfur dioxide,<ref name="queensland" /> and hydrocarbons.<ref name="queensland" /> Hydrocarbons are the main components of [[Petroleum|petroleum fuels]] such as [[gasoline]] and [[diesel fuel]]. These molecules react with sunlight, heat, [[ammonia]], moisture, and other compounds to form the noxious vapours, ground level [[ozone]], and particles that comprise smog.<ref name="queensland" /><ref name="epa-no2" />