50 years ago, when I was doing my HO layout, I was able to buy what we then called a "car re-railer". At least, this is what we called them back then. It was just a section of straight track, with more or less a fake crossing platform built into it, but it had wedge or v shaped pieces of plastic in each end, so that you could just take a car and roll it by hand back and forth across the track section, and it would put the wheels correction on the rails. You could also just space these around the layout, so that if one car became derailed, you could just have your engine keep pulling it until you got to this section, and it would put it right back on the rails, without stopping the train.
So far, I have not been able to find a track piece like this for O gauge track. I am probably using the wrong word for it in my searches. Any idea whether they make these and what they are called?