The most common and most likely answer to this crossword clue is the 7 letter word RAILCAR
I've seen this crossword clue in The Times
R
A
I
L
C
A
R
More clues leading to the result RAILCAR
- Drivers, one prevaricating about vehicle on track
- Complain bitterly about extremely dear carriage from US
- Bird snipped fish? It’s found on tracks
- There’s no end of bother behind bar in American’s carriage
- Reduced fare for coach?
- Coach: “Ride after thunder”
- U.S. coach right to oppose racial trouble
- Discount the odds of bacillaceae being found in Rolls-Royce heads’ vehicle
- One making false promises about endless protection in a vehicle
- Coach is writing on racial disturbance
Buddy explains!

The straight part
We know that "vehicle on track" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vehicle on track = railcar.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does RAILCAR mean?
RAILCAR noun- A self-propelled railway vehicle for passengers.
- Any railway carriage or wagon, a railway car.