I follow road guidelines. That is to say, if I’m turning off the road/lane I’m on, yes I indicate. The lane can be identified by lane border lines. The road’s junctions can be identified by gaps in said lane border lines, either bordering another road or becoming a dotted line. If you cross the line you indicate in all circumstances. Note, though, that I was taught in England, notorious for having the most in-depth and hardest to pass driving tests in the world.