## Data description

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 naming and types

Column nameData sourceLabelColumn descriptionExample
YEARNetwork ManagerYEARReference year2014
MONTH_NUMNetwork ManagerMONTH_NUMMonth (numeric)1
MONTH_MONNetwork ManagerMONTH_MONMonth (3-letter code)JAN
APT_ICAONetwork ManagerAPT_ICAOICAO 4-letter airport designatorEBBR
APT_NAMEPRUAPT_NAMEAirport nameBrussels
STATE_NAMEPRUSTATE_NAMEState in which the airport is locatedBelgium
FLT_TXO_UNIMP_2NM/airportFLT_TXO_UNIMP_2IFR flights with unimpeded reference time7290
TIME_TXO_UNIMP_2NM/airportTIME_TXO_UNIMP_2Total unimpeded reference taxi-out time in minutes60081
\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*}