Today I learned that highways and motorways are not the same. Every motorway is a highway, but not every highway is a motorway. According to Wikipedia a motorway is a “controlled-access highway”. The signs for those motorways as well was their basic setup were standardized by the “Vienna Convention on Road Signs and Signals” which has more than 60 participating parties around the world, making sure that driver’s licenses become more universal. A motorway, by the definition of this convention, is described as the following:

“Motorway” means a road specially designed and built for motor traffic that does not serve properties bordering on it, and that:

1. Is provided, except at special points or temporarily, with separate carriageways for the two directions of traffic, separated from each other either by a dividing strip not intended for traffic or, exceptionally, by other means;
2. Does not cross at level with any road, railway or tramway track, or footpath; and,
3. Is specially sign-posted as a motorway;

I came across that when being asked if one could use highway and motorway interchangeable. While starting from the premise that one could. a quick research showed, it’s not that easy. When you look into the details, you’ll find out that there are various definitions for both words, varying from country to country. I can highly recommend to read the referenced Wikipedia article.