The additional taxi-out time is a proxy for the average departure runway queuing time on the outbound traffic flow during congestion periods at airports.
It is the difference between the actual taxi-out time of a flight and a statistically determined unimpeded taxi-out time based on taxi-out times in periods of low traffic demand.
When monitoring taxi-out performance at airports, it is important to note that the goal is not to reduce taxi time to the unimpeded reference time - as this could negatively impact on runway throughput - but rather to reduce additional taxi-out time and associated fuel burn to the necessary minimum.
| Column name | Data source | Label | Column description | Example |
|---|---|---|---|---|
| YEAR | Network Manager | YEAR | Reference year | 2014 |
| MONTH_NUM | Network Manager | MONTH_NUM | Month (numeric) | 1 |
| MONTH_MON | Network Manager | MONTH_MON | Month (3-letter code) | JAN |
| APT_ICAO | Network Manager | APT_ICAO | ICAO 4-letter airport designator | EBBR |
| APT_NAME | PRU | APT_NAME | Airport name | Brussels |
| STATE_NAME | PRU | STATE_NAME | State in which the airport is located | Belgium |
| FLT_TXO_UNIMP_2 | NM/airport | FLT_TXO_UNIMP_2 | IFR flights with unimpeded reference time | 7290 |
| TIME_TXO_UNIMP_2 | NM/airport | TIME_TXO_UNIMP_2 | Total unimpeded reference taxi-out time in minutes | 60081 |
| TIME_TXO_ADD_2 | NM/airport | TIME_TXO_ADD_2 | Total additional taxi-out time in minutes | 15175 |
\[ \begin{align*} \text{Average unimpeded taxi-out time} & = \frac{\text{TIME_TXO_UNIMP_2}}{\text{FLT_TXO_UNIMP_2}} \\ \text{Average additional taxi-out time} & = \frac{\text{TIME_TXO_ADD_2}}{\text{FLT_TXO_UNIMP_2}} \end{align*} \]