Many Americans have abandoned their love of getting behind the wheel during the last year, and opted¹ to hop² on buses instead, according to a study released this week.

Inter-city bus service jumped 9.8 percent between the fourth quarters of 2007 and 2008, the highest growth rate in more than 40 years.

"The growth in intercity bus traffic is being driven by a number of factors, chiefly the spiking³ price of fuel over the past year," said Joseph Schwieterman, professor of public service and director of the Chaddick Institute, who directed the study, released on Monday.

"The basic economic efficiencies of bus travel are proving to be extremely attractive in this difficult economic climate," he said.

The revival⁴ of downtown districts and a growing acceptance of bus travel among younger travelers are also partly responsible for the U.S. bus renaissance⁵, the study found.

The study includes all arrivals and departures of all conventional intercity bus companies, such as Greyhound Lines and Continental⁶ Trailways, as well as curbside bus operators, but not commuter-bus operators.

Much of the growth was driven by two companies, Megabus and Boltbus, a joint⁷ venture of the Greyhound and Peter Pan bus companies, which started curbside pick-up service in northeastern states in spring 2007.

The two companies offer high-frequency service between major U.S. cities and wireless⁸ Internet service on board.

Growth in passengers choosing to take the bus has also had an environmental impact. Over the past year, bus route growth has reduced carbon dioxide emissions⁹ by an estimated 36,000 tons and 3.48 million gallons of fuel, according to the study.

The number of Americans who traveled by car dipped 3.3 percent in the first eight months of 2008.

本周公布的一项调查显示，在过去一年中，很多美国人“忍痛割爱“，以乘公共汽车代替开车出行。

今年第四季度，美国城市间公交客运量比去年同期增长了9.8%，涨幅为40多年来最高。

查迪克研究所负责人、指导该研究的公共服务学教授约瑟夫•施韦特曼说：“公交客运量的增大有很多原因，主要原因是去年油价飙升。”

他说：“事实证明，在经济困难时期，乘公共汽车出行的基本经济效率还是具有很大吸引力的。”

此外，调查发现，市区的复苏和越来越多的年轻人选择乘车出行也是目前公交客运量增长的部分原因。

该调查的主要对象包括“灰狗长途汽车公司”和“大陆客运公司”等美国所有老牌长途汽车公司以及经营搭车业务的客运公司，但不包括通勤班车公司。

经过调查这些公司所有班车的出发和抵达情况，调查人员发现，其中Megabus和Boltbus两家公司的客运量最大。Boltbus是”灰狗“和Peter Pan长途汽车公司的合资公司，从去年春季开始在美国东北部的一些州经营搭车业务。

这两家公司主要经营大城市间的客运业务，车次频繁，而且提供车内无线上网服务。

选择乘车出行的人增多对环境也有一定的好处。由于公交路线的增多，去年二氧化碳排放量减少了约3.6万吨，燃油消耗量减少了348万加仑。

今年前八个月，美国开车出行的人减少了3.3%。