I plan to ocasionally post about a random OSM tag which I believe should receive more attention. Due to usefulness or curiosity or even fun.
The first tag is
This is used to describe an emergency escape ramp, usually located at the lower end of a mountain, to help stop trucks or other heavy vehicles that are not able to stop while going down the road. It's a very useful traffic device, and literally life-saving.
Currently it's wiki page seems to be a rip-off of the wikipedia page. Let's hope it get's improved soon. :-)