For many drivers it is perfectly normal to drive into "Nienburg" via this bridge. As a cyclist, however, you will certainly have a sublime feeling of having ridden over there with your two-wheeler. A great building, which was built completely pedestrian: in / cyclist: in-friendly due to a large area of path in addition to the car lane.
So I didn't find the bridge particularly spectacular. Nienburg is definitely worth a trip, but I prefer to do the route with the racing bike and not "excursions" ;-) For that, I would rather take the touring bike.