What should you do now?

You answered correctly by choosing to accelerate and merge in front of the truck. According to German traffic rules, when merging onto a highway or performing an overtaking maneuver, you should adjust your speed to match the flow of traffic safely and merge smoothly ahead of slower vehicles if possible. It is important to accelerate enough in the acceleration lane to safely join the main traffic and avoid causing other drivers to brake suddenly.

Slowing down to merge between vehicles, especially when space and speed differences are unsuitable, is risky and can cause congestion or accidents. Therefore, the correct approach is to increase speed to create a safe gap in front of the slower vehicle (in this case, the truck) and merge there. This ensures smooth traffic flow and safe lane changes.