Does anyone know why there are plastic barriers on top of the concrete dividers on I-45?

Self-explanatory. I’m just curious if anyone knows what purpose they serve? They’re all up and down I-45, on top of the concrete dividers separating the express lane, and not even contiguous(they seem to be mainly on the dividers on the low points of I-45).

There’s already one section that is melted due to a car fire and another appears to be torn off, presumably due to a wreck, so they don’t seem to be very sturdy.

EDIT: I got some answers, thank you everyone. ☺️ Glad to see there are still friendly folks in Houston.