My question is: why don't the traderoutes follow the roads you have build?, and why is trade over land possible between cities who are *not* connected with a road?

A second question is: why can a traderoute change from a landroute in a searoute at places where no city or a port is build? This is in my opinion not realistic.

My suggestions for a next game version or patch are:

1. A traderoute over land must follow a road, railroad or a maglev. You can also use undersea tunnels as traderoutes. A big advance about undersea tunnels is that you can't attack them at sea for piracy.

As in our real world, in my ideas you have in the game roads who are realistic used as trade connections between cities. This make roads, but also railroads, maglevs and undersea tunnels as a strategical aspect more important and realistic as they already are in the game now. Also the places on land where you must protect your traderoutes against piracy are than more realistic. May-be it's a good idea that, where a railroad connection between trading cities is build, tradeunits who use that 100% railroad connection have a tradepoint bonus. This means that, by example, a caravan using a railroad have than two tradepoints and a freight six tradepoints. This is to simulate the higher speed trains have in relation to roadtransport. Speed is a critical factor in the capacity of supplylines. If you can travel faster, you need less units to maintain the same transport capacity. And again, if a maglev connection is build, the tradepoint bonus will be higher as on railroads. Tradeconnections using undersea tunnels have also there own tradepoint bonus too.

It's ofcourse important that nations who wish to trade over land, connect their road network with each other. During wartime is a connected roadnetwork between 2 nations very dangerous for the defending nation. It's
important that the computer ai knows this.

2. A tradeline over sea can only run from a coast square where a city or a port is build to another coast square where a city or port is build. And it would by great if you can place waypoints at sea for your tradelines. On this way you can avoid dangerous places at sea.

3. In the current game version international trade is, so far i know, only a interaction between the two trading nations. In my idea more nations can be a party in a traderoute between those two nations. This occur if a traderoute run over other territories also than only the territories of the two trading partners. If so they need the cooperation of the other 3rd and may-be 4th nation too. Such a 3rd party nation will get also income from that traderoute for using it's infrastucture. Ofcourse can the third party nation stop his cooperation if he like to do that. This option create another political weapon and also new strategical problems in the gameplay.

4. After the discovery of jetpropulsion it would be great if another tradeunit comes
available, the cargoplane. This tradeunit can
connect straight tradelines between 2 cities where airports are build and they don't need roads ofcourse. The cargoplanes are fast transport units and have because that a relative high tradepoint value, by example the same as freightunits on a railroad connection. Because the need for airtraffic control, and also political reasons, they can't violate the airspace of third party nations. So you need their cooperation too. Cargoplanes are vulnerable for airpiracy. A hostile nation can above sea threaten an airtraderoute with his fighterplanes and force cargoplanes to land on it's territory.

What do other people think about my suggestions?

If I was going to set up a Trade Rt system ala CTP2s, I'd have done it based on the movement points between the two cities. I think CTP2 does it based on simply the distance.

This way, the number of caravans required would be dependent on the movement points between the two cities. So, whereever a player built a road, the trade route would now take fewer caravans because the movement cost between the cities would now be lower.

Plus, like Aemilius was suggesting, now the trade routes would follow the roads, so the roads would become very strategically important. Imagine getting your troops in a position to pirate the one road that carried a bunch of trade routes between civs. Imagine what those civs would do to defend that road.

Two other little notes on trade routes. Shouldn't the destination city get some money from the trade route? Getting the trade goods pouring into a city would be beneficial to that city. Take a look at the Italian cities involved in the Spice trade with the East. In CTP2, that would be a trade route running from the East to say Venice. The city in the East with the Spice would be getting all the money. However, historically you'd have to say the Italian cities receiving the spice benefitted quite nicely from the trade route. The country with the resource should get more, but both cities should benefit.

Also, if you pirate a trade route, both civs should get upset with you.