Vehicular means to do with vehicles — cars, vans, lorries, traffic. A sign reading no vehicular access means you may walk in but not drive.
It is a formal word and it lives on signs, in planning documents and in law. Vehicular traffic, a vehicular bridge, vehicular manslaughter in an American courtroom. Nobody says it in conversation: you say traffic, or driving. Its whole usefulness is precision — a council needs one word that separates people on foot from people in cars, and pedestrian and vehicular are that pair.
1adjectivevehicularRelating to cars and other road vehicles.
“The lane is closed to vehicular traffic.”
Latin
vehiculāris
English, today
vehicular
From Latin vehiculāris. by surface analysis, vehicle + -ar.
Etymology from Wiktionary, CC BY-SA