I came across hobo symbol system in Richard Sproat‘s „Symbols: An Evolutionary History from the Stone Age to the Future“. In an overview of non-linguistic symbols systems he groups hobo signs with Gaunerzinken, signs used by German-speaking vagabonds. The body of research for them was more skewed towards crime as most analysis was done as part of police investigations. Would really recommend this book as a non-professional level introduction on the topic.

It was decades ago that I hitchhiked from Anchorage, Alaska to Moses Lake, Washington. I remember a specific place in Alaska though where I was hanging around in more or less the middle of nowhere by the side of the "highway" and there was a telephone pole or something near by. All manner of names were carved, many people from other countries, with the date they were there....

I confess I felt a certain sense of relief that I was not the only one that had ever stood in that desolate place hoping for a ride to come along.

I've been studying graffiti for the past few years. Documenting the art and culture of it. The majority of it is very focused around trains. You'll find the most graffiti around or near railroad tracks. There is a very distinct relationship between trains and graffiti.

Even to this day, there is still a ton of the hobo language and communication you can find on nearly every train. Living in the Midwest, its incredibly interesting when you see trains coming in from the East and West coast and the graffiti they still have on them from 10 years ago. The amount of doodles and philosophical thoughts are on every train.

There's so many people documenting this on social media now, its pretty cool.