How to acquire street signs? (Legally)

The city is currently doing a major road renovation near my house and it looks like they have placed two new traffic light posts on a road near my house complete with new signs. The old one is there there but I would like to get the two old signs for my room. Who can I contact about acquiring these signs? I assume they will just trash them and I think they would be a neat decoration

Edit: this is West U btw