Consultation on new Taxi and ASMA methodology

Rationale and background

The additional taxi-out time and the additional Arrival Sequencing and Metering Area (ASMA) time are used in several performance schemes as proxies for operational inefficiencies associated with capacity issues and/or techniques used to maximise runway utilisation at airports.

However, the currently used methodologies are often perceived to be complex and difficult to reproduce and several stakeholders have suggested a revision of the existing methodologies.

To address this stakeholder feedback and to actively involve them in the process, the Performance Review Commission created a Working Group on Additional Times in September 2021 (More information on the work of the group is available in the download section below).

Taxi out times at airports

The objective was to develop a new approach for the measurement of inefficiencies in the TMA at airports and in the taxi-in and taxi-out phase on the ground. The new methodologies should:

  • address the concerns regarding the existing indicators;
  • ensure easy reproducibility; and,
  • simplify and automate where possible.

The new approaches, as developed in the working group, are now available for public consultation in the download section below to get feedback from all interested stakeholders. The respective files contain a description of the methodology as well as a data file with calculated results. Complementary, there is a document available which addresses frequently asked questions (FAQ) which are relevant for all three methodologies.

We look forward to receiving any feedback you might have before 12/12/2022.

Comments should be provided by email to in the Comment Sheet available for download below.