another vehicleคัน is a classifier for vehicles such as cars, motorcycles, and buses; อื่น means “other” or “another.” It can also be translated as “another one” when the vehicle is understood from context.
TH: ถ้าคันนี้เสีย เราจะไปคันอื่นกัน
EN: If this vehicle breaks down, we'll take another one.