Service tax on gta services

Hello sirs..

in GTA services it has been specified that service tax payable under RCM only if value of taxable service exceed 750 per trip or 1500 per vehicle.

I want to understand the meaning of second codition i.e if value exceeds 1500 per vehicle. how to decide whether this condition is applicable or not. in what circumstances transportation charges are paid per vehicle??

please help me out for all this querries..