It's going to be costly defining where railroad property starts and finishes to establish who is trespassing. I've been challenged several times railfanning in the US when I was no where near the tracks, the authority stating I was still "on Company property". Here in the UK all the railways are fenced or walled in. Trespass on the railway here is a criminal offence, big fines, prison for repeat offenders and a criminal record, the latter meaning no more trips to the USA! Harold.