汉语说“高速公路”，说成英语可以是motorway, freeway, expressway等，但不能是highway；highway表示“公路”“交通要道”等。
英语词典对highway 的解释是：A highway is a main road, especially one that connects towns or cities. （尤指城市间的）公路（摘自《柯林斯高级英语学习词典第5版》）
例句：
Snow covered the highway. 大雪覆盖了公路。
I crossed the highway, dodging the traffic. 我避开车流穿过了公路。
This path joins the highway up ahead. 这条路在前面与公路相接。
The railway line runs parallel with [to] the highway. 铁路线和那条公路平行。