My school runs a shuttle bus service through all of the major off campus (but very near) apartment complexes. In prior years, the busing was contracted out to RTS, the regional public transit service. These were full size city buses: 4-5 regular buses in service at any time and one bendy bus as well.
Two of the routes have particularly difficult corners for a 40′ bus to make. One is illustrated below.
Perkins gate entrance
The route proceeds from the bottom right corner, makes a right turn between the sign and the curb, and then an immediate left turn into the complex.
The RTS drivers handled this turn with aplomb, and occasionally flair. Shoutout to the driver I saw drift an evening bus through that turn in the snow.
The service is now contracted out to First Transit. First Transit is running approximately the same distribution of buses that RTS was, although the buses now wear RIT livery, instead of RTS blue and advertising.
The First Transit drivers do not handle that turn with aplomb.
About a month back, a bus got stuck making the right turn. Single section buses are rear axle drive: the right wheel pair rode up on the curb, and then dug into the mud on the grassy side of the curb. The bus was unable to drag the wheel pair back over the curb. It’s hard to tell because of the water, but the depression is about 8-12 inches deep, which is about the depth of the tire on a bus (about one third of the total radius of the wheel).
going into the turn
halfway through the turn
and back over the curb!
There is more than one bus with the right rear completely covered in mud which indicates that 1) buses change routes and 2) this has happened more than once.
Notice that the curb is shattering.
That is presumably the suspension of the bus dragging back over the curb.
There’s now a stake placed in the corner to enforce the bus not going over the curb. The drivers now creep around the corner. It’s probably very stressful.
There’s also a pretty intense mud+gravel smear going on there now.
The articulated bus seems to have less trouble making the first turn, instead clipping the embankment with the nose in the immediate left turn.
Those poor buses, that poor tree.
Posit that only one bus runs this route (despite evidence to the contrary). 3 mile route x 4 trips per hour x 10 hours per day x 5 days per week x 16 weeks per semester x 2 semesters per year equals 19200 miles per year, and 6400 trips. This discounts all of the weekend, evening, intercession, and summer term routes. Three or four failures isn’t bad but it’s still a problem.
A standard city bus has an expected lifespan of 12 years or 500000 miles, with at least one complete service/replacement/rebuild of brakes, suspension, engine, etc during that time. There have been new developments in low floor buses, for accessibility and passenger comfort reasons. I think RIT/First Transit is running that style of bus. However, the Wikipedia for articulated buses reports that the failure mode is
relatively rapid disintegration of the vehicle’s superstructure.
due to not having enough suspension for uneven roadway. It seems reasonable that single section buses could experience a similar issue.
RIT’s planning horizon is 10 years. This one hypothetical bus should last 26 years by optimistic mileage.
Maybe the curb isn’t a problem because the bus will outlive expectations simply by being low mileage.
Maybe the curb should be moved to facilitate the turn so the turn is easier, the buses don’t experience the wear (from going over the curb or creeping very slowly around the corners at the limits of their turning radius), the roadway infrastructure doesn’t experience this abuse, and the drivers are less stressed.
I propose a new curve to the curb: about 6 inches inside where the tracks in the mud are.
(If you want to know about the mileage buses receive, this article and this article have information. RIT is running some eco-friendly bus type, but I can’t find what specific kind it is.)