Highways

[UltiUSABall]

Dude, We Need to Add Highways And Exits. The Highways will Allow Cars to Drive Faster. And will Have 4 Lanes.
The Exits will Allow Cars and Trucks to Transfer Between Highways and Roads.

[kamnet]

Dude, We Need to Add Highways And Exits. The Highways will Allow Cars to Drive Faster. And will Have 4 Lanes.
The Exits will Allow Cars and Trucks to Transfer Between Highways and Roads.

While OpenTTD does not yet support an elevated, grade-separated highway, since version 1.10.0 we do have the NewRoadTypes infrastructure installed Via NewGRFs it supports multiple styles of roads, and developers can set speed limits. A few new sets (Ratt Roads, U&RaTT) have implemented high-speed highways. If you want to make them elevated, you'll have to use bridges, and you want offramps from bridges you'll need to build a small hill to run some road surface on to create ramp. But we're getting there.