Parking in tenfoot entrance

There's been a few people parking on the entrance to a tenfoot which we use to park behind our homes by our garages. The tenfoot is only just big enough for two cars to squeeze past (if you're a confident driver). And when a car parks on the entrance to it, it obstructs and sometimes stops us from using the tenfoot parking (which we pay for as part of our property renting). It concerns me as if an ambulance or fire engine ever needed to be down there, they wouldn't get past the parked car.

There's a couple of different cars parked there every day.