[GoldenRacer]

One that I've always thought is really cool since I heard about it is the base of street signs. Instead of being cemented into the ground, signs are commonly bolted to a base so that they'll break away when hit. Some even have an incline that will throw the sign up and over your car. After learning this, I've started paying attention to signs I pass on walks or while driving and it's crazy how they are everywhere and I never noticed.

Here's a link with some more information: https://99percentinvisible.org/article/breakaway-hit-street-...

Another thing to look into if you find that cool is guard rail design. Modern guard rails have some cool features designed to reduce risks associated with hitting them.