The noun 公路 (gōnglù) means 'highway' or 'road.' It specifically refers to public roads, especially major routes between cities. It is distinct from 马路 (street) or 高速公路 (expressway/freeway).
这条公路连接了两座大城市。
Zhè tiáo gōnglù liánjiē le liǎng zuò dà chéngshì.
This highway connects two major cities.
他们计划在山区修建一条新公路。
Tāmen jìhuà zài shānqū xiūjiàn yì tiáo xīn gōnglù.
They plan to build a new highway in the mountainous area.
公路两边种满了高大的树木。
Gōnglù liǎng biān zhǒng mǎn le gāodà de shùmù.
Both sides of the highway are lined with tall trees.