People saw a need for free transportation, and they wanted to help control pollution.

人们看到了免费交通的必要性，他们想帮忙控制污染。

youdao

When something has to come from far away, obviously there is transportation, be this plane, train, truck, or ship, transportation involves pollution.

商品从远方运过来，自然需要用飞机、火车、卡车、轮船等来运输，而这些运输就涉及到污染。

youdao

The study also found that battery-electric vehicles and hydrogen fuel-cell vehicles recharged by WWS options would largely eliminate pollution from the transportation sector.

研究还发现利用WWS资源充电的电池汽车和氢燃料电池汽车有助于大幅降低交通领域的污染。

youdao

And the dymaxion car -- which could have provided safe, pollution-free transportation using little gasoline -- was never produced.

VOA: special.2010.05.30

But pollution is not the only environmental concern with transportation.

VOA: special.2010.01.11

Most of the data comes from the industrialized world. Not surprisingly, burning fossil fuels for transportation and electrical generation top the list for their contributions to climate change, acid rain and toxic pollution.

VOA: standard.2010.06.04

They could be employed in more creative ways for journalistic investigations into land use, or industrial pollution, or transportation.

FORBES: TMZ's Possible Drone Deployment

Mr. HINCHMAN: We've chosen the stricter California program because it's the only policy option available to us that we can use to reduce pollution emissions from the transportation sector, which is the most polluting and fastest-growing problem in terms of air quality in the Northeast.

NPR: States Push Automakers on Fuel Efficiency

In the Environmental Protection Agency this clearly lies in your area of responsibility, yet if it is about pollution created by airplanes, the Department of Transportation shares oversight.

FORBES: 3 Things Business Can Learn From Government