You are driving on a road that has several marked lanes going in one direction. When should the alternate merging procedure be employed?

Your answer is correct because the alternate merging procedure (known as "Reißverschlussverfahren" in German) is applied in two main situations: first, when a lane ends, and second, when a lane is obstructed and cannot be used continuously due to an obstacle. This procedure ensures smooth and fair merging by having vehicles from both lanes take turns to enter the continuing lane, preventing traffic jams and accidents.

The third option is not correct because on the motorway, merging lanes ending are handled differently, often with acceleration lanes that require adjusting speed rather than strictly alternating merges. Understanding when to use the alternate merging helps maintain orderly traffic flow and safety.