| Variable | Category | An immediate set of DMSs | The second set of DMSs | ||
| Number of crashes | Percentage | Number of crashes | Percentage | ||
| DMS type | Standard | 51 | 86.4% | 48 | 82.8% |
| Travel Time | 8 | 13.6% | 10 | 17.2% | |
| Incident info posted | Yes | 32 | 54.2% | 21 | 36.2% |
| No | 27 | 45.8% | 37 | 63.8% | |
| Incident type posted | Yes | 32 | 54.2% | 20 | 34.5% |
| No | 27 | 45.8% | 38 | 65.5% | |
| Incident location | Yes | 29 | 49.2% | 21 | 36.2% |
| No | 31 | 52.5% | 37 | 63.8% | |
| Severity blockage | Yes | 27 | 45.8% | 19 | 32.8% |
| No | 32 | 54.2% | 39 | 67.2% | |
| Severity delay | Yes | 2 | 3.4% | 1 | 1.7% |
| No | 57 | 96.6% | 57 | 98.3% | |
| Message posting timing (min) | 0 | 11 | 18.6% | 8 | 13.8% |
| 1 to 5 | 15 | 25.4% | 10 | 17.2% | |
| 5 to 10 | 4 | 6.8% | 2 | 3.4% | |
| >10 | 1 | 1.7% | 0 | 0.0% | |
| Message dissipated distance upstream the crash (mi) | 0 - 0.5 | 6 | 10.2% | 0 | 0.0% |
| 0.5 - 1.0 | 7 | 11.9% | 0 | 0.0% | |
| 1.0 - 1.5 | 4 | 6.8% | 1 | 1.7% | |
| 1.5 - 2.0 | 6 | 10.2% | 2 | 3.4% | |
| 2.0 - 3 | 6 | 10.2% | 4 | 6.9% | |
| >3.0 | 2 | 3.4% | 14 | 24.1% | |
| Exit Ramp present | Yes | 32 | 54.2% | 57 | 98.3% |
| No | 27 | 45.8% | 1 | 1.7% | |