If I'm with a group and leading, I'll probably do your stupid hand signals if and when it's safe to do so.

When I'm riding solo, which I do quite often... no more hand signals from me.  That should be the 'standard' for solo riders... imo.

 

Only time I’ll use a hand signal is when I pass a group, and I’ll give a friendly thank you wave then signal how many more are coming.  Nothing more ridiculous than a group of sleds all riding together and theyre all holding up 3-2-1 signals, when theyre all in plain sight.  I get it dude, keep your hands on the bars and in control of your sled.

Most of the trails I ride on are twisty and tree lined.  I can sometimes see the next sled's headlights through the trees and sometimes not.  It's kinda nice to know how many more to expect, but some of these trails are so narrow that it's probably better to just assume someone is coming and keep a finger or two on the brake lever.

I actually saw one of those lights this year and didn't realize what it was until the sled was past me.  Not sure what the different colors mean, for me it probably doesn't matter anyway (In the eyes of the FAA, I'm barely able to pass the color test on my flight physical).

yellow is more in my group and green is last sled in group, never guess that nobody else is behind them. 

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I think I’ll just stick to assuming there’s more riders.  My old eyes have enough trouble with runway lights.