Vehicles on our roads are now mostly petrol and diesel (柴油) cars, but their days cannot continue for much longer. A recent university study found that current electric cars could be used for 87 percent of daily car journeys in the US. That figure could rise to 98 percent by 2020.
One hurdle to the widespread adoption of electric cars has been "range anxiety" — drivers' concerns about running out of electricity on a journey. While petrol stations are conveniently located across national road systems, the necessary network of electric charging stations is still being developed. That said, charging points are becoming increasingly common throughout the USA．
Attitudes towards electric vehicles have changed greatly over the last few years. Not that long ago, electric cars were met with distrust, and their high prices drove customers away. Thanks to improvements in battery capacity, recharging times, performance and price, the current generation of electric cars are starting to persuade picky consumers. Plug-in cars will soon give internal combustion engine (内燃机) models a run for their money.
As well as development on the road, electric vehicles are taking to the seas and skies. Electric boats are among the oldest methods of electric travel, having enjoyed several decades of popularity from the late 19th to the early 20th century before petrol-powered outboard motors took over. Now, the global drive for renewable energy sources is bringing electric boats back. Steps towards electric air travel are also being made, with Airbus and NASA among the organizations developing and testing battery-powered planes. The experiments could soon make commercial (商业的) electric flight a reality.
Electric vehicles do not produce any emissions (排放). If the US could replace 87 percent of its cars with electric vehicles, it would reduce the national demand for petrol by 61 percent. However, because of the production processes and the generation of electricity required to charge these vehicles, they cannot claim (声称) to be completely emission-free. That said, as many countries continue to increase their use of renewable energy sources, electric vehicles will become even cleaner.
