I think we should have the option of allowing other civs to travel across your territory if they pay a toll, i.e. a diplomacy option of pay toll, declare war or leave. The toll could be negotiable.

This could also be a useful way of getting your units across another civs territory without signing a Right of Passage.

Good idea. Or have it as a buildable item(like fortresses) which could cover all the roads within five spaces. Of course you'd have to reserch Extortion first;)

Tolls could be used for luxuries carried throughout our territory.

The computer already knows if trade can go through your territory (roads/harbors) and knows it stops in time of war so why can't your country benefit from this trade. After all lots of commercial countries did not produce anything but they either retrade goods or simply taxed them to their benefits.

Ex: for each territory a luxury passes through you should pay an extra 2 to 5 % that goes directly to the treasury of the country it goes through. That would make developping a trade system pretty useful.

What about if when you sign a passage agreement you have the option to chosse what roads the AI can use. Like a fix route or something

"Toll for passage" is essentially a one-sided ROP agreement. That would open up some interesting possibilities. In addition to at least getting paid for the AI's wandering units a more formidable feature would be extorting a ROP for yourself in peace-negotiations without you giving a ROP to them in return. This would allow you to garrison troops on their territory "for security and peacekeeping reasons." :)

Of course, to make this work the AI needs to be able to take use of it too, and have strategies how to counter it, or it wouldn't be much fun. Improving the AI might mean a major work, though...

Why not just introduce a one-sided ROP under diplomacy?

Tolls may be applicable insofar as canals, which is a topic for another thread, but it seems like you guys are trying to overcomplicate this.

That's what we do better, dexters also dreaming doesn't cost.

Tolls should go through the sea if you own land on a coast, like how UK got rich off the Suez Canal. That would be cool too.