The poem sets two scenes side by side: the late arrival of spring in New England and the aftermath of what seems to be a fatal accident. Drivers slow down to stare as police and medics move around, and a body is carried out under a sheet. The speaker compares this to Michelangelo, as if we are all being asked to cover up something too raw to look at.
The thaw becomes a kind of uncovering. Snow hides "our most fragile things," then withdraws "like a sheet," just as the body was hidden. The smooth, easy rhythm of driving is broken by the sudden sounds "pop smack shatter," which suggests a crash, though the poem never says so outright.
The mood is hushed and uneasy. The final lines, where people "fumble" for their glasses, show a helpless wish to understand what has happened. Spring promises renewal here, but it also exposes loss, and no one seems ready to see it clearly.