Good retaining walls make for good neighbors

You probably can't drive down any highway or freeway and not see the scars and cosmetic damage caused by out of control cars striking and scraping the concrete retaining walls placed between the opposing lanes of traffic.

I wonder how many high-speed head-on collisions a day never occur because of the barriers. A common-sense safety measure that I would lay good odds no one ever thinks twice about. But every mark on those walls represents a potential horrible accident where the results or complications from accidents were at the least minimized.