Comment by Animats

If TechShop were still alive, I'd be tempted to build that. I have to move cans about 150 feet. I miss doing building projects, but don't do enough to have a real shop.

The rack and pinion thing was overkill. The steel wheel was never going to have enough traction, but big rubber wheels probably would have. The vertical guide rail, though, is nicely unobtrusive.

All-wheel drive is an option. Put rubber tires under each trash can, with a worm gear and a flexible drive shaft to the next car. Like a Shay narrow-gauge logging locomotive. Maybe integrate the power car with one of the cargo cars and eliminate the "locomotive".

The big problem here would be compatibility with the local Recology robotic garbage trucks.[1] The cans have to be spaced about 2 feet apart so the big gripper can grab them. (Otherwise, the driver has to get out of the truck, and they hate that.) The robot isn't that good at positioning the cans back exactly where it found them, although it does try. So getting them back on the train would be tough.

[1] https://youtu.be/AK3uPcWCNLo?t=150