Florida lawmakers pass bill allowing radioactive material to be built into Florida roads

[ProfessorGAC]

9. It's An Alpha Emitter

So, water would block emissions. My understanding is that phosphogypsum is a radon 226 carrier. Radon emits alpha particles which are greatly moderated by water.
So, when they won't need roads 20 feet underwater, the contaminated asphalt will be safer.
Doesn't seem like much of a bright side.