I'm nearly out of floridian snakes from my last trip (which means I need to go back soon!). This was the last species to turn up. I got a hot tip on the exact stretch of road to find these on and sure enough I turned up 3. This is the scarlet snake, Cemophora coccinea, a small snake which spends most of its time under ground or cover but which emerges at night.
Lampropeltis triangulum elapsoides, but it can be distinguished by, among other things, the lack of patterning on its belly. I think the flattened head on this guy (an adaptation for its fossorial lifestyle) is rather cute as is the pink tongue.