Yes, that very thing occired in south-central Pennsylvania. A rail line south out of York was out of service, and a group wanted to put a trail on the roadbed. However, another organization got some state funds and rehabbed the track and began running dinner trains on it. The two groups finally came to terms and now a bike/hike path runs next to the track. The line had been double track at one time, so there was plenty of room for both. Even so, there were those who wanted a fence to separate the two users.