Table 2.
Summary Statistics of Model Explanatory Variables
| Mean | Stand. Dev. | Min | Max | |
|---|---|---|---|---|
| Terminal Characteristics | ||||
| Dimensions (acres) | ||||
| Dock area | 1.9 | 0.6 | 0.7 | 3.4 |
| Yard area | 24.2 | 11.5 | 8.0 | 55.7 |
| Shop area | 0.4 | 0.5 | 0 | 1.6 |
| # of Dock doors | 147.9 | 45.1 | 60 | 260 |
| Equipment | ||||
| Forklifts | 36.4 | 17.0 | 11 | 73 |
| LH tractors | 52.8 | 68.7 | 0 | 230 |
| P&D tractors | 38.6 | 21.7 | 0 | 95 |
| Employees | ||||
| Dock workers | 94.4 | 68.9 | 11 | 388 |
| LH drivers | 115.7 | 109.8 | 0 | 386 |
| P&D drivers | 40.8 | 20.7 | 4 | 79 |
| Mechanics | 16.2 | 16.7 | 0 | 64 |
| Hostlers | 23.0 | 14.9 | 2 | 49 |
| Office workers | 34.3 | 34.4 | 0 | 103 |
| Hostler tractors | 5.8 | 4.9 | 0 | 27 |
| Total employees | 212.7 | 231.8 | 3 | 919 |
| Other Location Data | ||||
| AIRS AQS PM2.5 (μg/m3) | 12.1 | 5.5 | 5.7 | 23.8 |
| Wind speed (km/hr) | 13.6 | 6.0 | 5.6 | 38.2 |
| Temperature (C 0) | 14.0 | 9.6 | −8.7 | 37.1 |
| Precipitation (centimeters) | 0.1 | 0.6 | 0 | 7.4 |
| Relative humidity | 69.6 | 16.8 | 15.4 | 100 |
| Barometric pressure | 29.2 | 1.2 | 24.1 | 30.4 |