This corner of Utrecht was designed in the 1960’s when the paradigm was cars, cars and more cars. The roads had a 50 km/hr speed limit and weren’t exactly friendly to pedestrians or cyclists.
The city redesigned (“modernized”) the area by blocking access to a few streets, narrowing the streets, lowering the speed limit, and adding more greenery.
It was observed that just putting up a lower speed limit sign wouldn’t change driver behavior so long as the roads looked like a “through street”. Hence it was necessary to change the design to streets which looked like quiet residential area roads.