piggybacking
n.— «Sometimes schools will have a student start the lesson by driving another student home, a practice known as “piggybacking.” If there is another student in the car, ask where your teen will be driving and whether the route is suited to his or her abilities.» —“Student drivers get safety checklist” by Tony Bizjak Sacramento Bee (California) Apr. 19, 2008. (source: Double-Tongued Dictionary)
Further reading
In 1916, a small-town newspaper in Pennsylvania printed a fanciful item about a local gathering with a guest list that included, among others, Miss Ella Vader, Mr. Ray Zor, and other punny names. This is part of a complete episode. Transcript of...
A newscaster covering treacherous driving conditions offered this advice: Keep it between the mustard and the mayo. In other words, “Make sure your car stays between the yellow line and the white line on the road.” This is part of a complete episode...