Wiktionary
multivehicle
a. Involving more than one vehicle.
Usage examples of "multivehicle".
Nothing much exciting except for a multivehicle, multi-injury accident on the Interstate 66 exit ramp at the Theodore Roosevelt Bridge.
The highway itself is colorless and the sides of it look chewed on, and there's litter, and the median strip is dead grass with a whole lot of different tiretracks and skidmarks striping the sod for dozens of miles, as if from the mother of all multivehicle pileups sometime in I-26's past.