Some universities are so large that they have their own bus systems.

这些大学很大，校园内有自己的公共汽车。

youdao

New York, especially, has one of the largest and most useful subway and bus systems in the world.

尤其是纽约拥有的市内地铁和公交车系统就是全世界最大、利用率最高的地区之一。

youdao

He points out that some parks operate bus systems so visitors do not drive through protected areas.

VOA: special.2009.09.28

If companies adopted work-from-home cultures, would they reduce their carbon footprints by cutting down on employee commuting, de-congesting highways to create space for effective rapid bus transport systems, and reducing need for space and energy-devouring office buildings?

FORBES: CSR And The Job Hunt, More Thoughts

Rogoff has had an instrumental role in advising policy makers on the operating and capital needs of Amtrak, including the initiation and financing of high speed Acela service, as well as the financing of dozens of new light rail and bus rapid transit systems across the United States.

WHITEHOUSE: THE WHITE HOUSE

The city needs a debate about whether to favour bus rapid-transit systems, or more expensive but faster and higher-capacity metro lines.

ECONOMIST: Better late than never