Should've just use this

At least it provides better visibility than ninja speedbump, and since its not metal, less likely to be stolen by metal thieves.

They're meant to collapse upon impact, yes.

But the thing is, nobody would wanna hit them willingly if they can see the lines of lane divider from the distance.

It's meant as a warning & lane split indicator anyway.

Of course there's no cure for stupidity & ignorance.