Because of the variant traffic compositions of heavy vehicles and intercity buses, the prediction of travel time becomes more complicated and difficult to get a reliable predicted travel time.

• 由于我国高速公路上重车与客运车数量佔交通量比率大且变异程度高，致使欲取得较可靠的高速公路旅行时间预测资讯变得困难且复杂。