Two more things this made me remember, at least based on the savoir vivre in Poland (not sure if that's part of the culture in Germany too): - It's considered

Two more things this made me remember, at least based on the savoir vivre in Poland (not sure if that's part of the culture in Germany too): - It's considered very polite (kinda gentleman-grade polite) to change to the left (i.e. higher-speed) lane when you see a car building up speed to join the traffic from an acceleration lane (on the far right), to open a place in the traffic for them. That said, it's not "mandatory": you should only ever consider this as a lowest priority gesture, i.e. if noone's in sight getting ready to overcome you on the left. Conversely, if you're already driving fast on the acceleration lane and have trouble merging into the main traffic, and are already approaching the end of the acceleration lane, I've heard it recommended to stay on the subsequent "emergency lane" instead of e.g. reducing speed to a halt and trying to merge (or, obviously, forcing your way into some other car in the main lanes). It feels kinda risky, but the alternative of outright stopping, although it may feel tempting from basic instincts, is actually a huge immediate danger to you and everyone around. - If you notice an unexpected, sudden congestion ahead, it's also considered good manners to blink your emergency lights, to signal a danger to drivers behind you. That said, I personally find it a rather difficult feat, given that if the congestion is sudden and unexpected, by definition it means I'm surprised by the situation, and thus quite busy handling the car and the gear trying to decelerate quickly but safely, while looking in all the mirrors and ahead at once to actively monitor the situation around. Searching for the rarely-used emergency lights switch is a risky distraction.