When server population is under 10 there should be enough equipment to go around.
Sometimes what you see is players strafing equipment , which can prompt racing to a plane before it is vaporized.
It's a little different enforcement with a lower population. When the server is full Taxi is something most of the Admins will prioritize.
This is not an entirely accurate telling of the rule. The rule itself does not state anything about the number of players on the server.
The admins are allowed to apply reason to their application, and if the taxi driver did NOT steal the plane from a fellow player who was running to it, and did NOT negatively affect their team in any way, then there is no foul. However, no matter the number of players in the server, if the taxi driver is stealing the plane from a running teammate, or if jeeps are piling up on the runway due to the taxi drivers, the rule should be enforced.