| Variable | Category | Indicator | Units |
| Independent Input Variable | Resource use | Fuel consumption | Metric tonnes |
| Employment | Number of employed persons | Numbers | |
| Traffic volume | Trips per day | Numbers | |
| Meteorological situation | Rainfall | mm | |
| Relative Humidity | % | ||
| Temperature | °C | ||
| Solar Radiation | MJ∙m−2 | ||
| Wind Direction | ˚ from True N | ||
| Wind Speed | Knots | ||
| Dependent (Undesirable) Output Variable | Environmental pollution | PM2.5 pollution | µg/m3 |
| PM10 pollution | µg/m3 | ||
| SO2 pollution | µg/m3 | ||
| CO pollution | µg/m3 | ||
| NO2 pollution | µg/m3 | ||
| O3 pollution | µg/m3 | ||
| Dependent (Desirable) Output Variable | Economic gains | Transport share of GCP | Ksh. |
| Wage situation | Average monthly wage | Ksh. |