Why are different buses quicker or slower?
Because of the routes they take through the campground and the number of stops.
From the Outpost, the Yellow bus turns right at the 4-way stop sign, then only has 4 stops (1600-1900, 1500, 1400, 300-500), then it stops at Settlement. (that's where you get off for the restaurants and marina).
From the Outpost, the Purple bus turns left at the 4-way stop sign, then has approximately 4 stops through the cabins, then stops at Loop 2000, then stops at the Group Camping area, then takes a back road to the Settlement.
From the Outpost, the Orange bus turns left at the 4-way stop sign, then has 4 stops through the cabins, then backtracks back to the 4-way then continues on down the center of the campground and has 3 more stops down the center road, then stops at Settlement.
Because the Yellow route DOES NOT go past the cabins and has fewer stops, it makes the run quicker. Quite frankly, there also seem to be fewer folks actually using the internal buses on the Yellow route also. Many have golf carts and/or bicycles, so those four stops quite often are just stop, open the door and continue on.
There are MANY more folks staying at the cabins that don't have bicycles or a golf cart and depend on the internal transportation. So the stops involve more folks getting on and off at each stop.
The Orange route also includes a stop at the main pool and recreation area, so there are lots more folks using the Orange route to visit that area of the campground, so stops take longer on the Orange route also.