We have an 80 kph sign about 6m after the autoweg sign (100kph), why they didn't combine them is anyone's guess. My detection system always misses it, and often there are speed checks. Fortunately I can disable sign recognition for the cruise control.

Wait does your cruise control automatically accelerate by default when it thinks it sees a sign..? That sounds terrifying! I've only seen systems which give you a prompt to switch speed which you can accept with a button