What is the correct course of action on this one-way road?

You answered correctly by waiting until the roadwork workers allow you to drive past. This is the correct action on a one-way road with a temporary obstacle like this.

In German traffic rules, reversing on a one-way road or making a U-turn is generally not permitted unless absolutely necessary and safe, especially if there is a risk of endangering other road users. Since the road is narrow and blocked by the work truck and a worker, reversing or turning around would be unsafe and likely illegal.

The proper procedure is to wait patiently for the workers to signal that the road is clear, ensuring safety for everyone involved. This respects the rules of cooperation and safety during roadworks, which always take priority over regular traffic flow.

Remember: On one-way streets blocked temporarily, always wait for official signals or permission to proceed instead of trying to turn around or reverse.