| Code Value | Definition |
|---|---|
| 0 | None |
| 1 | Road Surface Condition (wet, icy, snow, slush, etc.) |
| 2 | Debris |
| 25 | Toll Booth/Plaza Related |
| 26 | Backup Due to Prior Non-Recurring Incident |
| 27 | Backup Due to Prior Crash |
| 28 | Backup Due to Regular Congestion |
| 3 | Rut, Holes, Bumps |
| 4 | Work Zone (construction/maintenance/utility) |
| 5 | Worn,Travel Polished Surface |
| 6 | Obstruction in Roadway |
| 7 | Traffic Control Device Inoperative, Missing or Obscured |
| 8 | Shoulders (none, low, soft, high) |
| 9 | Non-Highway Work |
| 98 | Other |
| 99 | Unknown |