Eli5: Why Jersey Barrier often being used at the center of the highway rather than using guardrails?

Question

Eli5: Why Jersey Barrier often being used at the center of the highway rather than using guardrails?

In: 2

Answer 1

A guardrail is expected to give a bit, absorbing the impact of a vehicle and bringing it more gradually to a halt. This is great if on the side of the road but not so great when pushing the barrier back a bit might mean it is now in the way of oncoming traffic.

Guardrails are also by necessity permanently installed with posts driven into the ground. Driving these directly into the surface of the road would be difficult, compromise the road surface, and be permanent. A Jersey barrier is capable of being relocated while also stopping vehicles from moving past them into oncoming traffic.