There was heavy traffic on the roads.

路上的交通很拥挤。

There is heavy traffic in the downtown area tonight.

今夜闹市区交通繁忙。

In recent years many cities are faced with the problem of heavy traffic.

近年来，许多城市都面临着交通拥挤的问题。

That bridge is too weak for heavy traffic.

那座桥不太牢固，承受不住过多的车辆。

There are numerous high buildings, heavy traffic, and dense population in modern cities.

现代都市到处高楼耸立，交通拥挤，人口稠密。