公路(gōng lù) - road, highway in Mandarin

公路 (gōnglù) means "road" in the sense of a proper, made-up route for motor traffic between places, closer to "highway" than a small residential street. 公 (gōng) means "public" and 路 (lù) means "road, path", so it is literally a "public road", built and maintained for everyone's use.

You will meet it compounded constantly: 高速公路 (gāosù gōnglù) is "motorway, expressway" (公路 (gōnglù) with "high speed" in front), and 公路旅行 (gōnglù lǚxíng) is a "road trip". A country road out between villages is still 公路 (gōnglù), while a narrow street inside a town is 街 (jiē) or 马路 (mǎlù) instead.

Don't confuse it with the plain 路 (lù), the general word for "road, path, way" of any size, from a garden path to a motorway. 公路 (gōnglù) specifically flags a road built for cars over some distance, so use it when talking about driving between cities, not for giving someone directions down the street.