Since this seems to be a non-stop issue, has anyone looked into low-cost, effective remedies? Training always fails when the trainee isn't paying attention -- even the best "real shooter" has a brain fart now and then.
I was thinking, maybe a simple railing along the yellow line, where the shooters have to walk to a entrance/exit "hole" in the rail. There could even be a chain for the last person out during a cease fire to connect between the rail sections as a "gate" to stop people from entering.
Sometimes water pipes can be obtained cheaply, like when a building is demolished or renovated by the government. With the right flanges and connectors, the rail could be installed cheap enough.
Make the entrance/exit locations about 2-3 shooter positions apart, so someone at lane 2 might have to cross the yellow line at position 1 or 3. Add to the signs "No going over or under the railing."
That's just one, initial thought I had. Any physical barrier is bound to stop the majority of brain farts. Faded yellow paint on the floor doesn't seen to be enough to remind people to not cross it.
I'm not saying lack of a barrier is an excuse. Just that an ongoing problem has been identified, and telling people to stay home isn't really a solution. I would think coming to the range more often would do more to teach than keeping them away.