Goal: I am looking for suggestions on how to craft multiple entrances for a fortress, most likely 12 (3 per side of the map), near the map edges.
Reasoning: I'm currently embarking on in a Terrifying location, where the local fauna is all variety of undead nasties and the local weather is enthralling clouds. The clouds roll in frequently, at least a few per week. In this same map, I've lost more than a handful of migrants to the clouds, and pretty much every caravan that's tried to approach my fort was dead before they even made it to my fort entrance. I want to put around 9-12 additional entrances to my fort at the far edges of the map, to allow caravans and my migrants to have at least a chance of making it to the front door.
Ideas on ways to do this safely? Even with an entrance 2 tiles from them, migrants still beeline for the 'main' center entrance.
I tried digging highways at Z -1 and tunneling upward. That works for the first highway, but after that the dwarves *insist* on going back to where I embarked and first struck the earth and then frolicking on the topside to dig the downward staircases. I tried setting the underground highways to high traffic, and that didn't work. A friend suggested I do that, then additionally set the surface to restricted, which I'll try. What I also will try to do is build the highways out 1 by 1, and as I finish each one, stick a door near the end and make it impassible to give the dwarves no other foot traffic option.
It is pretty hilarious to see the elven caravan show up and walk right into the middle of a cloud, then watch them tear each other apart.