Actually, no, when the road is being overhauled, the town can come back with you with another invoice. See "Straßenbaubeiträge" [1]. Sometimes, these are prohibitively expensive, forcing homeowners to abandon their property, often amounting to several 10k Euros [2].

[1] https://de.wikipedia.org/wiki/Stra%C3%9Fenbaubeitrag [2] https://www.youtube.com/watch?v=BPdigJ6dOL8