To wake up the drivers who aren’t paying attention or are dozing off. They put them on the shoulders of the highway here east of the city where the drivers are notorious for passing on the shoulders and causing serious accidents. Also rumble strips might wake up the kids sleeping in the back seat so they start screaming and slow their parent down.

Tennessee has them too, it warns you either there's a stop sign ahead. Danger ahead or railroad crossing.

Tennessee roads are better

[media=https://m.youtube.com/watch?v=jUJMfSdFKLg]