Answering my own question: "These crashes often led to vehicles flying at high speed into the very objects which guardrails or barriers were supposed to protect

Answering my own question: "These crashes often led to vehicles flying at high speed into the very objects which guardrails or barriers were supposed to protect them from in the first place. To address the vaulting and rollover crashes, energy-absorbing terminals were developed." https://en.wikipedia.org/wiki/Traffic_barrier#Barrier_end_treatments https://en.wikipedia.org/wiki/Traffic_barrier#Barrier_end_tr...