It is well known that the start/end of a road safety barrier is the most hazardous part of the system. The main risks involve spearing of the errant vehicle or an abrupt stop beyond biomechanically survivable thresholds. While a ramp down end terminal removes the spearing risk, it creates a new risk of vehicles vaulting.
All w-beam/guardrail ends should be treated with a MASH compliant Gating Redirective Energy Absorbing Terminal (in Victoria we call them G.R.E.A.T terminals). See the approved list here:

Let us know some of the products you use in the comments.

Video source: Fifth Gear