| Clue | Source | Date |
|---|---|---|
| One runs from Me. to Fla. | New York Times | 31 Oct 2021 |
| 50 from Calif. to Md., e.g | New York Times | 30 May 2018 |
| 50 from Calif. to Md., e.g. | ||
| Hwy. number lead-in | Premier Sunday | 15 Oct 2017 |
| Any Interstate, for example | ||
| American hwy. number lead-in | ||
| Numbered 31-Down |