society > travel > means of travel > route or way > way, path, or track > road > [noun] > road of specific class (4)
second-class road: a road of a second class; a B-road (see B, n. 4b(b).
Chiefly British. Denoting the highest category of road below a motorway.
In various specific applications. a second-class road.
(originally U.S.), a Class III road.