Eli5: how does gps update new roads

Question

An intersection in my town just converted from a 4 way light to a roundabout, and the gps was changed to reflect within a week. Who does this and how???

In: 58

Answer 1

Basically states and governments have planning systems for new areas and changes to roads, map makers buy this data. Then a lot of apps like google maps, apple maps, Pokemon go add more data, which is then sold/used to improve the map.

Old system used aeroplanes.