And idiots try to drive on it to skip traffic.

There are shoulders in Germany as well, but they prefer that the ambulance drive through the middle lane.

Right? Around here, each side of a divided highway has two travel lanes marked. There is a narrow shoulder on the left, and a wide shoulder on the right, either of which is adequate for emergency vehicles.

The intended purpose is to facilitate future construction. There is enough room on each side of the median for three lanes plus a narrow shoulder. They can put up a temporary k-rail median and repaint the lane lines to move a lane of traffic across the normal median. They can completely close a lane of traffic for repairs, while retaining at least two lanes (plus a narrow breakdown lane) in each direction.