She's the only one who figures out that you can get off the road and drive on the grass verge, allowing her to drive when everyone else is stuck in a massive traffic jam. Apparently no one around there had ever driven in Boston. About now the first part of the comet hits, in a special-effects extravaganza that you already saw if you watched the commercials and the trailers. This is a water hit off Hatteras, like I said. Somehow the wave hits New York City before it hits a spot where the highway sign clearly labels the location as being six miles from Virginia Beach.
Young love survives.
The astronauts blow up the bigger part of the comet successfully. Since momentum isn't conserved, all of the gravel doesn't hit the earth in a semi-solid lump of equal mass to the original body. Other than the priest who shows up to marry Leo and Sarah, there's no religious feeling at all in the flick. Now there are a few more movies that could have, should have, been made. The story about the people in the caves, for example.