[pierreh]

So in marlande, you have that one crossing subway tube fairly close to the edge of the city border there. If there was some way you could move that a  few more tiles further away from the border, I would be curious if this helps balance the traffic more ?

Actually, that subway crossing was a mistake. In my 'doctrine' about subways, such crossings are an absolute no-no - I explained why in my long 'subway rant' quite a while ago in this CJ. Here is an enlarged view of it:



This has meanwhile been corrected. I rerouted the east-west subway tube, to remove the crossing. The new routing is shown in this picture; the old route is represented by a dotted red line:



The new route for the subway line, and the other line to which it runs in parallel to Desognes, cross a GLR at the station, so there should be no adverse effect of that crossing. The new route doesn't carry any traffic yet, because it is not yet connected on the other side, in Desognes. This will be done the next time I play Desognes. Since I play my cities in round-robin fashion, I'll get back to Desognes later, and to Marlande too. I expect to deal further with the inter-city traffic in various ways.