A sign post assembly includes a core assembly. The core assembly includes an impact absorbing mechanism and an elongated post. The impact absorbing mechanism includes an anchoring plate including a through hole, and a first elastic impact absorber. The elongated post has a proximal end and a distal end. A flange is disposed at the distal end of the post and rests on a top surface of the first elastic impact absorber with the post extending through the through hole in anchoring plate. A dimension of an outer surface of the post is less than a dimension of an inner surface of the through hole and the flange has a peripheral shape that prevents the flange from passing through the through hole.