Here’s the thing: there’s more than one government in the world, and they don’t all use consistent highway classification systems.

OpenStreetMap is a global project. While there are some regional tagging differences, the general aim is to keep things as consistent as possible around the world. This makes it much easier to actually use the data.

If everyone copied their local government data directly into OSM, wouldn’t we end up with an inconsistent mess that’s harder for developers to use?