Pacers were
really common in the era of the SRR/NS steam program. I chased and rode a few of these trips and what would happen would be someone would hold position with the locomotive and prevent anyone else from getting past or getting good pacing shots of their own...
Until someone else could get around them, immediately slow down and push the first guy back, out of position. the first guy would usually lose his mind, somehow feeling entitled to pace the entire way.
I'm told a guy wasn't having it once (I think the story was pacing 2716), stayed in his position and let the 'interloper' slow down and strike the front end of his vehicle, forcing the second guy off the road. Pacer boy just kept going, and a quick phone call to the po-lice from the guy who got hit got a "boy, yew's in a heap o' trouble" discussion with the Sheriff down the road for the pacer jerk.
Those trips always seemed to be nowhere near a good highway to get around them. The Jacksonville NRHS trips weren't too bad, as there was a decent highway between Jax and Valdosta, and you could usually get in front of the train for chasing shots with minimal issues because the state highways rarely were within sight of the tracks.
As for this 4014 mess, I think most would agree with me when I say I'm shocked this didn't happen 20-30 times the first trip for 4014. It's the primary reason I didn't want anywhere near this trip. I've never been one for large gatherings, anyway.
-Lee
Flickr photo set of my On30 layout