Trade routes through CS ally territory

[void_genesis]

Just played a nice cultural win with Persia, latest version VEM on the steam cloud.

Noticed I could get one of my own cities connected to a trade route through an road through an allied CS's territory (yellow/black icon came up on my city).

However when I tried to connect that city to other nearby CS's with the road request there was no response. I even tried breaking the road with a worker then rebuilding it- no dice. Looked close and only one needed to cross a river and a bridge was evident.

Any ideas?

 

[Thalassicus]

Trade route connections are done in the game core only Firaxis has access to.

 

[void_genesis]

Thanks for the reply. I just thought it was strange that my city was connected, but it couldnt connect to any further CSs. Ho hum.....