On the road to Mexil I found the roadkill-snake shown above.
Even though the critter was only about 15 inches long (38 cm) and looked dead as could be, my heart skipped a couple of beats. Part of that was the automatic response any normal human feels when nearly stepping on a snake, but part was that this snake definitely puts you in the mind of "coral snake," which isn't a kind of snake you want to fool with.
We have several snake species here who mimic venomous coral snakes, and this is one of them. Similarities include the bold banding, the blunt head hardly differentiated in size from the rest of the body, and the black snout and forehead. The most obvious feature separating this snake from real corals is that it is predominantly black, while the coral snakes' black bands are much narrower on predominantly red bodies. Other more technical and dependable differences can be noted -- this snake has nine or ten supralabial (above-the- lip) scales while corals have seven, for instance -- but my experience is that when you have a coral or a look-alike before you, doing something like counting scales above the critter's lip gets hard.
My roadkill was the Short-faced Snail-eater, DIPSAS BREVIFACIES, a nocturnal snake who eats snails, which it somehow extracts from their shells before swallowing them. It's limited in distribution to the northern Yucatán Peninsula, including east-central Belize and specializes in tropical dry forest habitats.