I'm an Amtrak Assistant Conductor out of Oakland. I've been on quite a few trains out here where parents dump off UMs on our trains. They're required by Amtrak policy to have a copy of their UM paperwork and to present it to the Conductor. The Conductor/ A.C. is then only allowed to turn the child over to the adult/ parent/ family member at the UMs destination. UMs under the age of 11 are only allowed to ride between staffed stations and during daylight hours only.
A lot time this does not happen. The parent goes in and buys the ticket for the UM and the station agent doesn't know he/she are selling a ticket for a UM. I've worked trains from OAK (our symbol is OKJ for Jack London Square) to SAC on Sunday evenings when parents send their kids back to their custodial parents. A few of them have the proper papers and we can somewhat can control it.
On the San Joaquin trains, however, I've UMs without the proper paper work, especially on 715 out BFD on Sundays which I've seen loads just from BFD as high as 250 alone! There are only two of us, plus the LSA and SA to watch out for them. I can't even count the times I've seen single males hit on teenage UMs. I wish we had the controls the airlines had.
Amtcndtr35