De or het carpoolparking?

The correct Dutch article is:

de carpoolparking

Rule Words ending in -ing: almost always de. See the rule

How to use carpoolparking

the carpoolparkingde carpoolparking
this carpoolparkingdeze carpoolparking
that carpoolparkingdie carpoolparking
our carpoolparkingonze carpoolparking
your carpoolparkingjouw carpoolparking
every carpoolparkingelke carpoolparking
which carpoolparking?welke carpoolparking?
a big carpoolparking / the big carpoolparkingeen grote carpoolparking, de grote carpoolparking