When a bunch of kids get in a car (most likely a VW Bus, most likely with tons of drugs, and drive to an exotic destination (like Vegas or New Jersey).

It happened more in the 70s.

A lengthy sexual encounter that might involve multiple positions, oral sex, sex toys, dress-up, etc.

When everyone goes drivin around in the spot where the least amount of cops roam and toke toke toke it up.

Visiting my fucking in-laws on psychotropic drugs.

using "herbs" while in a car

When someone references an event or conversation that happened a long time ago or around people who you would need to explain it to.

A Road trip is a car trip that is defined by the word "trip". The trip is a not the journy but a feeling that you get after smoking to much.