| Clue | Source | Date |
|---|---|---|
| Train track foundations | USA Today | 25 Jul 2020 |
| Street surfaces | Newsday | 21 Jun 2015 |
| Train track supporters | Premier Sunday | 22 Feb 2015 |
| Street surfaces | ||
| Train track supporters | ||
| Track foundations | ||
| Track foundations | ||
| Track foundations | ||
| Unpaved surfaces | ||
| Supports for ties and rails. | ||
| Underpinnings for ties. | ||
| Highway foundations. |