It’s usually not the cyclists who don’t get single file but the trail waddlers. They will be walking in a big clump completely blocking the trail and when you say “on your left” half of them move to the left and half to the right.
What happened Sunday was that the cyclist was coming from behind the two that were riding next to each other. There was a corner and he couldn't stop so he went of the road and crashed. There is a lot of people riding this way and sometimes when I say: to the left they also move one to the left and one to the right. Sometimes I even get an f off for good measure. These people don't even know that this is a rule or a safety issue.It’s usually not the cyclists who don’t get single file but the trail waddlers. They will be walking in a big clump completely blocking the trail and when you say “on your left” half of them move to the left and half to the right.
Everything you said is correct, however, there ARE lanes, the path is devided down the middle by a line. There would be no problems if everyone would stay in to the right in such a manner that it doesn't block the entire path. Also, these people didn't even stop to see if the person is ok and that is not acceptable regardless of who's fault it is. All I'm saying I to show some respect for the rules and each other!Personally, trials like these just aren’t safe enough for cyclist and pedestrian traffic unless they have separated traffic lanes. Beyond that there are way to many different skill sets/levels of cyclist making it unpredictable at best for some of the reasons you mention. Regardless of rules and etiquette ultimately you are responsible for control of your bike when you ride for your as well as the publics safety.
I posted a picture of trail rules. They clearly state to stay to the right and single file. That is the rule. Those that don't like it can go ride somewhere else.Sadly we can’t legislate kindness, respect and etiquette, and decent acceptable human behavior. Those traits are leaned, or not, at home.