Good point but I think it is already the case.

As the article says, this is not an ordinary school street.  A few months ago, the two entrances for cars have been barred to cars (https://www.openstreetmap.org/changeset/132370901 + https://www.openstreetmap.org/changeset/138672534).  So, the whole street is effectively car-free.

Maybe add access=no + foot=yes + bicycle=yes + motor_vehicle=permit on those streets, to give an additional hint through rendering.