IPA: //ˈroʊdˌwɜrθnəs//
KK: /ˈroʊdˌwɜrðnəs/
The quality or condition of a vehicle that makes it safe and legal to drive on the road.
Before taking a long trip, it's important to check the roadworthiness of your car.
Roadworthiness is formed from "road" (from Old English "rād", meaning a way or path) and "worthiness" (from Old English "wyrðnes", meaning the quality of being worthy). The term refers to the quality of a vehicle being fit or worthy to be driven on the road.
Think of a 'road' as a path and 'worthiness' as the quality of being suitable — together, they describe a vehicle's fitness for driving.