There’s no use denying it — autonomous¹ cars are coming. Experts says that partially² autonomous cars will be on the road by 2017, and that within a decade, fully³ autonomous vehicles will be zooming⁴ on highways and through our neighborhoods.

不容否认，自动驾驶汽车离我们已经不远了。专家表示，能实现部分自动驾驶的汽车将于2017年上路；不到10年，完全自动驾驶汽车将开始穿梭在高速公路和大街小巷。

When this day comes, though, what will become of the two car garage? It may not be needed anymore, according to a new study from the University of Michigan Transportation Research Institute.

等那一天真的来了，双车车库会有什么样的遭遇？根据密歇根大学运输研究院的一项最新研究，到时我们可能就不再需要这种车库了。

The study essentially⁵ posits⁶ this: if autonomous cars become the norm, they could be shared by two people in the same household. Say Jack⁷ and Diane are married and live in the center of a medium-sized city, one where there is no major public transportation to speak of. Their self-driving car could take Jack to his job in the suburbs, then return to the apartment, where Diane would get in and be shuttled to her job in another part of town. The two no longer need their own vehicles to get to work, and can share the one autonomous car without having to deal with car pooling or going out of their way.

该研究指出：如果自动驾驶汽车成为常态，两位家庭成员就可以同时使用一辆车。比如杰克和丹妮是一对夫妇，居住在一座中型城市的市中心。他们的自动驾驶汽车可以载着杰克到郊外上班，然后返回他们的公寓，载着丹妮去城里的另一个地方上班。两人无需分别开一辆汽车上班，也不必再为拼车之类的麻烦事操心，而是可以共用一辆自动驾驶汽车。

“This reduction in ownership and an accompanying shift to vehicle sharing within each household, in the most extreme hypothetical scenario⁸, could reduce average ownership rates by 43% (from 2.1 to 1.2 vehicles per household,)” the report says.

该报告指出：“家庭汽车拥有量的减少和用车模式的转变，在最极端的假设下，可能使家庭汽车的平均拥有量降低43%（每个家庭从拥有2.1辆车下降到1.2辆）。

As noted⁹, though, this is just the most extreme possibility. Brandon Schoettle, the lead writer of the study, said the actual reduction in car ownership could be much less than that, depending on a few factors. For instance, states may pass laws that prohibit such an arrangement by requiring autonomous cars to only operating with a human inside.

不过正如上文强调的，这只是最极端的假设。该研究项目的首席作者布兰登o舒特勒认为，受一些因素的影响，机动车保有量的实际减少幅度可能显著低于这个比率。比如，美国的有些州可能会出台法律，禁止无人驾驶汽车单独上路，而是要求必须有一名驾驶员坐在车内。

And even though driverless cars are starting to creep into the mainstream¹⁰, don’t expect this change to happen overnight. Schoettle said turning over the existing fleet of cars would take time, so any reduction in the number of cars on the road could take “decades.”

即使无人驾驶汽车已经开始潜入主流，但这种改变也不会一夜之间发生。舒特勒表示，要淘汰现有数量的汽车需要很长时间，所以要想看到路面汽车数量明显减少这一幕，可能还得等上“几十年”。