In recent years, high-grade highway is growing with unexampled speed.Some of them, which were constructed in early days, have been or are to be widened because of too much traffic.

• 近年来，高等级公路的建设正以前所未有的发展速度向前推进，早期修建的高等级公路其交通量陆续达到饱和状态，公路加宽势在必行。