The guard rails are pretty good enough as is. When you hear of something like this it's very often caused by lack of maintenance/poor installation/assembly. There is a guy on youtube that has videos of a whole bunch of guardrails that are simply unsafe because they are missing bolts or were assembled incorrectly.

And remember - guard rails are meant to slow you down enough to try and prevent a worse situation rather than always turning you back into the roadway to create a larger accident with other traffic or stop you completely.