For those who didn't read all the posts here:
I go to the pickup site. In daylight, I position the vehicle for a fast getaway, preferably where I can see the switch. At night, I aim the headlights where the crew member will be working. I scan the area for movement. The conductor gets off the train, goes to the switch mechanisms, operates them, the train slowly moves onto the spur. The conductor remains on the ground. He or she waits until all three engines and 115-125 cars go past at low speed. Then he/she realigns the switches for main-line passage. The conductor gets in my Suburban and we go find the head of the train and get the engineer.
I am not afraid for myself, I can leave, and pretty darn fast, too!
The conductor is not armed. It takes at least 5 minutes for the train to pass at 5+- mph. One switch is very near a popular water source for wildlife. The thought of driving away while someone's head is in a cougar/bear's mouth just doesn't appeal to me.
You don't think that a lit flare stuck in your face would discourage you?
This is a trashy, slave-labor job. I can't afford car insurance, much less a gun.
"Optimum" is not an issue here.
Flares seemed to be the safest, most convenient, most useful make-do weapon that could be thrust into the face of a predator with a reasonable amount of accuracy without injuring the conductor (much). A flare might also discourage a predator from coming closer.
Thank you all for the recommendations.
Sue