noun, masculine/ka.ʁɑ̃.bɔ.laʒ/plural: carambolages
a carom, a cannon; pile-up (car accident involving 3 or more cars hitting each other successively)
“Les carambolages sont des accidents typiques d'une vitesse excessive et d'un trafic dense. On en voit surtout sur les autoroutes.” — Pile-ups are the product of excessive speed and high traffic density. They happen most often on highways.
From carambole + -age.