Getting rid of trade carts?

I recently reinstalled MTWII and got that emulation problem, so I downloaded the new .exe file that lets you actually play the game, but now on the campaign maps the settlements spew out a constant stream of trade carts. Literally a long line of them which slows it down considerably. Is there any way of making the trade carts not display on the campaign map?

well, I don't know about modding map graphics, Im Sorry

Anyone?