Steps to reproduce (assuming Pak128.Britain-Ex):
1. Start server
2. On server, create new world. Make sure that there is at least one city, and that "intercity road length" is set to 9999
3. Start client
4. On client, create new world with "intercity road length" set to 0
5. On client, connect to server
6. On server, as public player, build a cattle farm near a city
7. On server, cattle farm should be connected to city by road
8. On client, cattle farm should not be connected to city by road
9. Client may have already desynced. If not:
10. On server, place bus stop on section of new road created by cattle farm.
11. Client should have now desynced.
Thank you for that report. I believe that I have now fixed this; I should be grateful if you could re-test with the next nightly build.