Byway and Dual carriageway

Byway noun - A side road little traveled (as in the countryside).

Dual carriageway and byway are semantically related. In some cases you can use "Dual carriageway" instead a noun "Byway".

Dual carriageway noun - A highway divided down the middle by a barrier that separates traffic going in different directions.

Byway and dual carriageway are semantically related. Sometimes you can use "Byway" instead a noun phrase "Dual carriageway".