| Clue | Source | Date |
|---|---|---|
| Pre-sign sign | LA Times Daily | 13 Feb 2021 |
| Pre-sign sign | The Washington Post | 13 Feb 2021 |
| Sign indicating a sign | New York Times | 21 Jun 2019 |
| Road sign | Thomas Joseph | 05 Feb 2019 |
| Sign indicating a sign | ||
| Warning about reaching a braking point | New York Times | 17 Nov 2017 |
| Warning about reaching a braking point | ||
| Road warning | Newsday | 12 Feb 2016 |
| Pre-sign sign | ||
| Pre-sign sign | ||
| Pre-sign sign | ||
| Road sign #4 |