pilot vehicle

Short definition from Wiktionary

Noun

1. 1
   A vehicle that ranges ahead of a convoy/train/transport: A vehicle used to warn other road users of the presence of an oversized vehicle/combination
2. 2
   A vehicle that ranges ahead of a convoy/train/transport: Synonym of pilot engine / pilot locomotive: An engine that runs ahead of a train to clear the route
3. 3
   A lead vehicle
4. 4
   A lead vehicle: Synonym of pilot engine / pilot locomotive: The leading engine locomotive in a multiple heading train
5. 5
   A tending vehicle
6. 6
   A tending vehicle: Synonym of pilot engine / pilot locomotive: A yard/station locomotive engine used to shuttle rail cars around a yard or station
7. 7
   A prototype vehicle, initial production vehicle, lead vehicle in a new manufacturing process, first vehicle produced in a new manufactory.
8. 8
   Used other than figuratively or idiomatically: see pilot, vehicle.