I find this very nifty. While you can’t see the numbers, the black bars tell you how parking spots are left. These are pretty accurate. Almost every parking garage or lot, or car park, I’ve been to with Joe or walked past has these. There are sensors under the concrete that can tell by weight if there is a car there (not sure if it works on motorcycles or mopeds/scooters).
In the Dundrum mall/shopping center parking lot (basically their Castleton), these type of signs will tell you how many spaces are available on each floor. Once you drive onto the floor, it tells you how many spaces are available in each row, and at this particular venue there is a green light above the available space. Imagine if Castleton and Keystone had this! No more row driving. If there is only 1 space left in a row though it could mean a broken sensor and not a space, so best to go to the row with 5 or 10+ left.