Data in support of the paper "Improving Efficiency Through the Publication of Expected Distances for Standard Terminal Arrival Routes". The data is organised in subfolders containing the data for each of the three analysed airports (LSGG, EDDM, LIRF). Each folder includes a landing_full.parquet traffic file that contains all analyzed trajectories for the respective airport, along with random subsamples of sizes 10,000, 5,000, and 2,500. Additionally, each folder also contains samples of 1000 trajectories following each of the four specific STAR procedure that were analysed per airport: LSGG: AKITO 3R, BELUS 3N, KINES 2N, LUSAR 2N EDDM: BETOS 1A, LANDU 1B, NAPSA 1B, ROKIL 1A LIRF: ELKAP 2A, LAT 2C, RITEB 2A, VALMA 2C Finally, each folder also contains a landing_df.parquet file that summarises the following key information about each of the trajectories contained in the landing_full.parquet file: ID A unique identifier linking the row to the corresponding trajectory data Typecode The ICAO typecode of the aircraft Start Timestamp when the aircraft passes the first waypoint of the STAR Stop Timestamp when the aircraft crosses the runway threshold Runway Designator of the landing runway STAR Name of the STAR procedure used by the aircraft Distance Total distance traveled by the aircraft from the initial waypoint of the STAR to the runway threshold