That, or using ROADTYPE_FLAG_HIDDEN on the ROAD label like Ufiby seems to have done screws with the AIs
I use it connected to the TOWN ZONE as a neutral road. So that the city can build a neutral road and depends on from the time epoch, so we do not pay attention to AI.
Another flag "ROADTYPE_FLAG_TOWN_BUILD" gives only conditionally. It is written in detail there
Enables the roadtype to be built by towns, picked by highest speed (defaults to ROAD if no speed limits?)
I don't agree with this one. Because it's inconvenient. Something I wanted to do, there is no result
First: hide the ROAD label, so that the quality is as a neutral road, so that the city can be built independently. But what about AI and what will happen to AI ?
Secondly. Set a different placemark on the flag ROADTYPE_FLAG_TOWN_BUILD in quality for the city to build a neutral road. The main label ROAD can be used for the player and the AI. But I wanted to limit the neutral road to low speed, in fact in the game you will no longer see the neutral road, only the city is worth the road with the highest speed, this is the ROAD