Kepp in mind it is a new bus system and they are getting some of the kinks out. WHile the route I was on, orange, was having problems the other 2 routes were fine. There aren't lines per say but there will be a wait regardless of where you stay. The only "line" I saw was waiting for a boat to MK. They run every 20 min or so so even if you can't get on the first one (never seen this happen, allthough I don't go during peak times) just know you only have to wait 20 minutes for the next one.
I think there aren't buses that are faster or more direct. Each route goes from the Settlement to the Outpost, just going through different areas of FW. If you are close to one than you are far from the other. Jus build in "travel time" and you should be fine.