I started this discussion because the mod does a poor job at explaining how to use it. Here's what you need to know.

1. The construction speed and the road level which can be constructed relate directly to your individual pawn's Construction level and Manipulation. When they are in a caravan a new tab will appear and you can click and see it.
   
2. ISRG is useless. Use ISRG2 because it solves virtually all the issues. With it all you need is pawns to work the road.
   
3. When pawns are working they don't need to rest. The game treats the caravan as "sleeping" so this is a major convenience. They can work 24/7.
   
4. To plan a road you must be with a caravan and the caravan should be stopped at a tile. The road will start from your caravan's location. Use left clicking to add new segments. Keep in mind that you can ONLY add segments which are next to the currently last segment.
   
5. To accept a road plan you can right click anywhere and then construction will begin.

---TIME AND RESOURCES---
One of the things which I haven't figured out is how many ISRG2s you need and if having more increases the construction speed. This is actually something which I find hard to test because there's always something happening. Personally when I send pawns to build, I take 4 ISRG2s so this is up in the air.

You should bring plenty of food. You don't need to bring any other resources related to the road at all.

From my personal experience, building an asphalt road is the ideal option. HOWEVER, since construction speed is a major factor, I strongly recommend using this mod with a mod which adds stronger prosthetics like Archotech or Ultratech. Otherwise, my personal advise would be to only build roads where you really need them.

Having other colonies build roads for you is a major boon if you can afford it, even if it's a dirt path. I always keep about 10k silver near my beacons just for this. I also use a mod which adds quest pawns to arriving caravans.

If you feel like the construction speed is too slow you can check out the mods listed below. Keep in mind that most of them will make your pawns much stronger:

- Ultratech prosthetics (a more balanced mod, which doesn't make your pawns overpowered): https://steamcommunity.com/sharedfiles/filedetails/?id=2808872704
- Archotech Expanded Prosthetics (use either this or the one above; this one makes your pawns MUCH stronger): https://steamcommunity.com/sharedfiles/filedetails/?id=1467604976