How do guard rails on the interstate actually work?

Question

I’m no engineer and obviously don’t understand physics very well, since I’m asking this question. But how can guard rails keep a car or semi truck driving 70+ MPH from leaving the road?

In: 4

Answer 1

70 mph is only the velocity in the forward direction. In case of lane departure, usually the vehicle is departing the lane at much less than 70 mph in that direction.