highway, skyway

Highway is not high in the sense that it is above the ground but vehicles can run as fast as the limit goes or even beyond the the limit per hour if the highway patrols can't chase. But skyway is above the ground and even if it's a skyway, we cannot travel always fast. It's just because it's above the ground that it's named skyway.

LOL! High doesn't mean the physical height but I think it's the movement and the number of vehicles that use the road and also the speed. Whereas skyway is built above the ground. Do you know that the space above the ground is called sky? And so the way built at some height above the ground is called skyway.

LOL! It's not because there's the word high that it is high above the ground like high blood pressure. I think it's called highway because of the volume of traffic and the speed of vehicles running there. It's skyway because it is above the ground.

I think originally, highways were all built elevated. As time progressed, people saw the need for a non elevated super high speed wide road. I guess that's how the non elevated highways were born. Skyways I believe are also just elevated highways. The developers just changed the name. After all, these projects are private and not public and so they have to market their service/product.