OpenStreetMap is a map that everyone can edit and improve, and that's how we've created the best map of the world.
Alas, some people just want to vandalise things . If you've seen weird things on the map (e.g. lots of crossing white lines), that could be vandalism. Here's what to do if you see this:
https://community.openstreetmap.org/t/have-you-spotted-vandalism-on-openstreetmap-org/114684
with thanks to @SomeoneElse.