Makes you wonder why mini-busses aren't more popular. Kind of like short school busses, but for adult transit. It seems that the smallest city busses you ever see are designed to hold at least 30 people still, but like you said, often times have only 5 people on them. You could use a GM full-size van frame at maybe 1/3 of the up front cost and probably 50% of the operating cost and still seat at least 8 to 10 comfortably. With smaller, cheaper mass transit, you could then operate, say, 50% more of them and improve ridership by offering more routes and more frequent pickups.