A road bridge has to carry a lot of traffic.

公路桥必须承载很多来往车辆。

There's always a lot of traffic at this time of day.

每天这个时候总是有很多来往车辆。

There's a lot of traffic jams.

这里有很多交通堵塞的状况。

There's a lot of traffic fumes.

有很多汽车尾气。