a broad highway designed for high-speed traffic
"After merging onto the motorway, we cruised past the city limits at sixty miles per hour to reach the coast before sunset."
A broad highway designed for high speed traffic, having restrictions on the vehicle types permitted and merging lanes instead of cross traffic; in parts of the United States and other places called freeway (or simply highway in other parts of the United States).
"After driving north on the motorway all morning, I finally reached my destination without seeing a single intersection or stop sign."
The word motorway is a combination of the words motor and way. It originally referred to a road specifically designed for motor vehicles.