Thompson UT UP maintenance truck (1768)

Though I've seen these rail/street pickup trucks for years, I've never seen one actually shift from rail to street use. I had always assumed that the wheels for running on the rails were operated by some hydraulic system with something that the driver controlled in the cab, so I was surprised when the driver got out and released a fairly simple spring-loaded switch that raised the rail wheels. It would be interesting to see how they line things up when switching from road to rail.