| Site | Barreiro | Cacilhas | Montijo | Seixal | ||
| PNC Increments during | Ferry Occurrences | 25% | 197% | 69% | 79% | |
| Departures | 179% | 59% | 249% | 170% | ||
| Arrivals | 43% | 25% | 35% | 79% | ||
| Regression Analysis | Ferry Occurrences | r | 0.79 | 0.91 | NSS | 0.94 |
| p | <0.01 | 0.02 | <0.01 | |||
| Departures | r | 0.80 | 0.92 | NSS | 0.93 | |
| p | <0.01 | 0.01 | <0.01 | |||
| Arrivals | r | 0.76 | 0.88 | NSS | NSS | |
| p | 0.01 | 0.02 | ||||
| Wind Speed | r | NSS | −0.93 | NSS | −0.85 | |
| p | <0.01 | <0.01 | ||||
| ANOVA(1) | p | <0.01 | <0.01 | 0.04 | NSS | |