They keep within speed limits.

他们保持在限速范围内。

Wales has introduced special low speed limits to minimise pollution.

威尔士推行了特定的低速限制，以最大限度地减少污染。

Some drivers simply ignore speed limits.

有些司机无视速度的限制。

The law lays down that speed limits must be obeyed.

法律规定，行车必须遵守速度限制。

Considering the problems of the existing speed limits at home and abroad which are base on design speed and running speed, speed limit theory base on safe speed is proposed in this paper.

针对国内外现有的设计速度限速和运行速度限速法所存在的问题，提出了基于安全行车速度的限速理论。

The speed limits on all roads are marked in miles per hour.

所有马路的限速标志都是以每小时多少英里标识的。

It isn't always easy for the police to enforce speed limits.

对警察来说要执行时速限制并不总是很容易。

Would we need traffic lights? Would we need lanes? How about speed limits?

我们还需要红绿灯吗？我们需要车道吗？限速呢？

You could set the roller speed limits as low as 15mph and as high as 200 KPH.

你可以设定辊车速限制低至15英里每小时和高达200公里。

Governments could create and enforce speed limits and make using seat belts mandatory.

各国政府可以制定并实施限速政策，同时强制使用安全带。