主干道，是连接城市各交通枢纽、全市性的公共场所，是客货运的主要路线；也可以说是贯穿城市各区的主要道路网络群。

城市的主干道，一般通过开路或扩阔的方法铺设。

对于城市的老区来说，开通路段对原居民会产生极大的影响，因此扩阔原本的狭小街道成为主干道是折衷的方法。

A trunk road, trunk highway, or strategic road is a major road, usually connecting two or more cities, ports, airports and other places, which is the recommended route for long-distance and freight traffic. Many trunk roads have segregated lanes in a dual carriageway, or are of motorway standard.