| Transportation is a major contributor to air | | | | broadly a factor in inactivity and obesity, which in |
| pollution in most industrialised nations. According to | | | | turn can lead to increased risk of a variety of |
| the American Surface Transportation Policy | | | | diseases.[37] |
| Project nearly half of all Americans are breathing | | | | Driverless cars |
| unhealthy air. Their study showed air quality in | | | | Main article: Driverless car |
| dozens of metropolitan areas has got worse over | | | | Fully autonomous vehicles, also known as robotic |
| the last decade.[32] In the United States the | | | | cars, or driverless cars, already exist in prototype, |
| average passenger car emits 11,450 lbs (5 | | | | and are expected to be commercially available |
| tonnes) of carbon dioxide, along with smaller | | | | around 2020. According to urban designer and |
| amounts of carbon monoxide, hydrocarbons, and | | | | futurist Michael E. Arth, driverless electric |
| nitrogen.[33]free articles directory | | | | vehicles—in conjunction with the increased use |
| Animals and plants are often negatively impacted | | | | of virtual reality for work, travel, and |
| by automobiles via habitat destruction and | | | | pleasure—could reduce the world's 800,000,000 |
| pollution. Over the lifetime of the average | | | | vehicles to a fraction of that number within a few |
| automobile the "loss of habitat potential" may be | | | | decades.[38] This would be possible if almost all |
| over 50,000 square meters (538,195 square feet) | | | | private cars requiring drivers, which are not in use |
| based on Primary production correlations.[34]free | | | | and parked 90% of the time, would be traded for |
| articles directory | | | | public self-driving taxis that would be in near |
| Fuel taxes may act as an incentive for the | | | | constant use. This would also allow for getting the |
| production of more efficient, hence less polluting, | | | | appropriate vehicle for the particular need—a |
| car designs (e.g. hybrid vehicles) and the | | | | bus could come for a group of people, a limousine |
| development of alternative fuels. High fuel taxes | | | | could come for a special night out, and a Segway |
| may provide a strong incentive for consumers to | | | | could come for a short trip down the street for |
| purchase lighter, smaller, more fuel-efficient cars, | | | | one person. Children could be chauffeured in |
| or to not drive. On average, today'sfree articles | | | | supervised safety, DUIs would no longer exist, |
| directoryautomobiles are about 75 percent | | | | and 41,000 lives could be saved each year in the |
| recyclable, and using recycled steel helps reduce | | | | U.S. alone.[39][40] |
| energy use and pollution.[35] In the United States | | | | Future car technologies |
| Congress, federally mandated fuel efficiency | | | | Main article: Future car technologies |
| standards have been debated regularly, passenger | | | | Automobile propulsion technology under |
| car standards have not risen above the | | | | development include gasoline/electric and plug-in |
| 27.5 miles per US gallon (8.55 L/100 km; | | | | hybrids, battery electric vehicles, hydrogen cars, |
| 33.0 mpg-imp) standard set in 1985. Light truck | | | | biofuels, and various alternative fuels. |
| standards have changed more frequently, and | | | | Research into future alternative forms of power |
| were set at 22.2 miles per US gallon (10.6 L | | | | include the development of fuel cells, |
| 100 km; 26.7 mpg-imp) in 2007.[36] Alternative | | | | Homogeneous Charge Compression Ignition |
| fuel vehicles are another option that is less | | | | (HCCI), stirling engines[41], and even using the |
| polluting than conventional petroleum powered | | | | stored energy of compressed air or liquid nitrogen. |
| vehicles. | | | | New materials which may replace steel car bodies |
| Other negative effects | | | | include duraluminum, fiberglass, carbon fiber, and |
| Residents of low-density, residential-only sprawling | | | | carbon nanotubes. |
| communities are also more likely to die in car | | | | Telematics technology is allowing more and more |
| collisions[original research?] which kill 1.2 million | | | | people to share cars, on a pay-as-you-go basis, |
| people worldwide each year, and injure about | | | | through such schemes as City Car Club in the UK, |
| forty times this number.[25] Sprawl is more | | | | Mobility in mainland Europe, and Zipcar in the US. |