文章大意：本文是一篇说明文，主要讲的是通过结合汽车共享和拼车（乘车共享）的概念，城市可以显著减少所需的汽车数量，进而带来一系列积极的效益，如降低移动基础设施的成本和能源需求、缩短旅行时间、减少交通堵塞和降低环境影响。
4 . On average, cars sit, doing nothing, 96 percent of the time. That makes them ideal candidates for the sharing economy. The potential to reduce traffic jams is enormous. A handful of car-sharing systems are already having a major impact on the total number of vehicles in our cities. Scholars have estimated that every shared vehicle removes nine to 13 privately owned cars from the streets.
The benefits will grow greatly as autonomous vehicles, that is, self-driving cars, currently available in experimental forms, gain a notable portion of the market. “Your” car could give you a lift to work in the morning and then, rather than sitting in a parking lot, give a lift to someone else in your family—or to anyone else in your neighborhood or social media community.
As a result, a single vehicle could go from one to 24 hours of use a day. A recent paper by our colleagues at the Massachusetts Institute of Technology report s that, under such conditions, the mobility demand of a city like Singapore could be met with only 30 percent of its existing vehicles. In addition to vehicle sharing, autonomy could open up a new wave of ride sharing. Already applications such as Via, uberPOOL and Lyft Line allow different people to share the same ride, cutting operating costs and individual fares. Autonomy could boost ride sharing even more because all trips could be managed online. In cities, the potential for ride sharing is significant, based on analyses by our Sense able City Lab at M. IT.
New York City, for example, is obviously shareable. Our lab’s HubCab project gathered data from 170 million taxi trips involving 13,500 taxis in the city—specifically, the GPS coordinates (协调) for all pickup and drop-off points and corresponding times between the two. We then developed a mathematical model to determine the potential effect of ride sharing applied to those journeys. The project introduced the concept quantitative results revealed how taxi sharing could reduce the number of cars by 40 percent with only rainimal delays for passengers.
Combine car sharing and ride sharing, and a city might get by with just 20 percent the number of cars now in use, with its residents traveling on-demand. Of course, such reductions are theoretical. In real life, they would depend on how willing people are to share rides and adopt self-driving technology. But any drop in the number of vehicles could lower the costs and energy associated with building and maintaining our mobility infrastructure (基础建设). Fewer cars might also mean shorter travel times, fewer traffic jams and a smaller environmental impact.
1. What does the author imply in the first paragraph?
| A．Car-sharing is still in its infancy. |
| B．Cars aren’t made full use of at present. |
| C．Privately-owned cars have decreased by 13%. |
| D．There have been fewer traffic jams in big cities. |
2. According to the passage, which of the following is a benefit brought by autonomous vehicles?
| A．They can reduce the mobility demand of big cities. |
| B．They will account for a large portion of the market. |
| C．They can make it convenient for people to share the same ride. |
| D．They will raise people’s awareness of environmental protection. |
3. New York City is an example to illustrate _.
| A．how trip-sharing has helped the city |
| B．how ride-sharing can be put into practice |
| C．why people are worried about taxi sharing |
| D．why mathematical models matter in making a city shareable |
4. Which conclusion is the author most likely to agree with?
| A．We should share not only cars but also rides. |
| B．People have no confidence in self-driving technology. |
| C．The estimated reductions of cars on streets are theoretically groundless. |
| D．Our mobility infrastructure cannot support the development of autonomy. |
