Step 1.
google map can find parking lot POI, but it does not know whether it is owned by private company or owned by government. Google also mix with some business have its own parking lots.
Google map is not a good way to do this task.
Step 2.
work around, find all parcels owned by government, if owner name is goverment.
Then use google map to compare whether it is a parking lot or a park, or a building.
select all parcel owner is a government agency
Step 3.
not all of them are government, these are noise, need remove, the rest of them are good.
Step 4.
blue is government owned parcel,
use google map to compare whether it is a parking lot or a park, or a building.
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