Public transport is the primary form of motor transport. Whilst in the western world private cars dominate, in the developing world, which represents the majority of the global population, private car ownership is prohibitively expensive (for example, in dense urban areas through the high cost of parking), and walking, (motor)cycling, and public transport are often the only practicable options, with only the latter being viable for longer distances. This often takes the form of mini-buses that may follow fixed routes but are usually flexible, including taxi-style door-to-door transportation
Public conveyances that travel on roads alongside private traffic are often slower than private transport because ordinary vehicular speed of travel is further burdened, in the case of public transit, by service headways (wait times for passenger vehicles), connections, and frequent stops to board additional passengers. Use of some public transport systems may take up to two or even three times longer than an equivalent trip in a private vehicle, especially where transfers are required or headways are long. The challenge of headways, connections, and stops generally cannot be alleviated, so improvements to the speed of public transit often have focused on increases to vehicular speed beyond that of private traffic by means of the use of dedicated or semi-dedicated travel lanes (grade-separated, elevated, or depressed rights-of-way) and traffic light preempts
Public transport in general has a smaller footprint per rider than private motor transit, and thus has a significant advantage in areas with higher population densities because land space in such areas is at a premium. Cost is not the only relevant factor. In densely settled areas, traffic congestion frequently slows private motor transit to a crawl.
The term rapid transit, is often used to distinguish modes of transit possessing a dedicated right of way and having frequent, continuous service. Still, rapid transit often fails to live up to the name, as there are no firm guidelines as to how fast transit must be to be rapid.Light rail is another form of public transit, comprising of a tram or trolley operating on a rail line.
Emissions from road vehicles account for over 50% of U.S. air pollution. For every passenger mile traveled, public transportation uses less than one half of the fuel of private automobiles, producing 5% as much carbon monoxide and less than 8% as much as the other pollutants that create smog such as nitrogen oxides. Scientists estimate that public transportation already reduces emissions of carbon dioxide, which contributes to global climate change, by over 7.4 million tons annually.
If Americans were to use public transportation at equivalent rates as Europeans, scientists estimate that U.S. dependence on imported oil would decrease by more than 40% and that carbon dioxide emissions would be reduced by more than 25%. However, in almost all cases, public transit systems in the United States have had almost no impact on the number of drivers.
Public conveyances that travel on roads alongside private traffic are often slower than private transport because ordinary vehicular speed of travel is further burdened, in the case of public transit, by service headways (wait times for passenger vehicles), connections, and frequent stops to board additional passengers. Use of some public transport systems may take up to two or even three times longer than an equivalent trip in a private vehicle, especially where transfers are required or headways are long. The challenge of headways, connections, and stops generally cannot be alleviated, so improvements to the speed of public transit often have focused on increases to vehicular speed beyond that of private traffic by means of the use of dedicated or semi-dedicated travel lanes (grade-separated, elevated, or depressed rights-of-way) and traffic light preempts
Public transport in general has a smaller footprint per rider than private motor transit, and thus has a significant advantage in areas with higher population densities because land space in such areas is at a premium. Cost is not the only relevant factor. In densely settled areas, traffic congestion frequently slows private motor transit to a crawl.
The term rapid transit, is often used to distinguish modes of transit possessing a dedicated right of way and having frequent, continuous service. Still, rapid transit often fails to live up to the name, as there are no firm guidelines as to how fast transit must be to be rapid.Light rail is another form of public transit, comprising of a tram or trolley operating on a rail line.
Emissions from road vehicles account for over 50% of U.S. air pollution. For every passenger mile traveled, public transportation uses less than one half of the fuel of private automobiles, producing 5% as much carbon monoxide and less than 8% as much as the other pollutants that create smog such as nitrogen oxides. Scientists estimate that public transportation already reduces emissions of carbon dioxide, which contributes to global climate change, by over 7.4 million tons annually.
If Americans were to use public transportation at equivalent rates as Europeans, scientists estimate that U.S. dependence on imported oil would decrease by more than 40% and that carbon dioxide emissions would be reduced by more than 25%. However, in almost all cases, public transit systems in the United States have had almost no impact on the number of drivers.
No comments:
Post a Comment