StVO § 5 overtaking
(1) It is left to overtake.
(2) Only those who can overlook the fact that during the entire overtaking process, any hindrance to oncoming traffic is excluded. Furthermore, only those who drive at a much higher speed than the one to overtake may overtake.
(3) Overtaking is prohibited:
1. in an unclear traffic situation or
2. if it is prohibited by an arranged traffic sign (signs 276, 277).
(3a) Anyone carrying a motor vehicle with a maximum authorized mass of more than 7,5 tonnes shall not overtake, without prejudice to other overtaking prohibitions, if the visibility due to fog, snow or rain is less than 50 m.
(4) If you want to avoid overtaking, you must behave in such a way that the endangerment of the following traffic is excluded. When overtaking, a sufficient lateral distance to other road users, especially those walking and cycling, must be observed. If you overtake, you have to get back to the right as soon as possible. Whoever overtakes, must not hinder the one who is being overtaken.
(4a) The overtaking and re-ordering shall be announced in good time and clearly; The direction indicators are to be used.
(5) Outside built-up areas overtaking may be announced by short sounds or illuminated signs. If the driver is blinking with high beam, oncoming vehicle drivers may not be dazzled.
(6) Who is overhauled, must not increase his speed. Who leads a slower vehicle, the speed must be reduced at a suitable location, if necessary, wait, if only so several immediately following vehicles overtaking is possible. For this purpose, also suitable side stripes can be claimed; this does not apply to motorways.
(7) Anyone who announces his intention to turn left and has arranged himself is to be overtaken on the right. Rail vehicles are to overtake on the right. Only those who can not, because the rails are too far to the right, may overtake left. On lanes for one direction, rail vehicles may also be overtaken on the left.