# Analysis of Traffic Organisation in the Kiss-and-Fly Zone of Krakow Airport: Eye-Tracking Study
## 3 Field Study
### Equipment and Participants  
The data were collected using Tobii Pro Glasses 2 (Tobii AB, Danderyd, Sweden) and then processed in the Tobii Pro Lab. The device looks like normal glasses and is easy to wear due to its light weight and slim design. This specific model of eye-tracking spectacles allows recording typical parameters such as gaze, fixation, fixation duration and saccade. For the purpose of this study, the duration of one gaze was set as 0.02 s as well as the duration of one fixation--0.08 s (four gazes). Also, it was assumed that one fixation could be interpreted here as one observation. That is why, within the scope of this study, the words \"fixation\" and \"observation\" will be used as synonyms. The Tobii Pro Glasses Controller software version 1.86 was used to calibrate the device for each participant. The test vehicle was an estate car, with a kerb weight of 1170 kg, equipped with a 1591 cm\({}^{3}\) petrol engine and manual gearbox transmission. Distances to the eyes from the ground level and from the hip-point were 120-130 cm and 63 cm, respectively, which is within the standard limits [37,38]. Although Tobii Pro Glasses 2 has a camera installed viewing in the direction of driver's gazes, and the vehicle was additionally equipped with a front dashboard camcorder (30 frames per second, resolution 1920 \(\times\) 1080 pixels), which was recording videos of the view in the direction of a car movement. Taking into account that drivers can turn their heads when driving, such a device allowed us to obtain more complete information concerning the situation on the road ahead and its surroundings. When wearing eye-tracking glasses, the task of participants during the experiment was to reach by car a ground access of Krakow Airport from the starting point, find the K&F zone there and stop in this zone for a moment, imitating the drop off/pick up of passengers. After that, the drivers had to leave the K&F zone and the airport surface access in the direction from which they arrived (i.e., to the east of the airport--the first exit in Figure 1). Driving tests were carried out during July and August of the year 2020 when the air transport traffic all over the world was drastically reduced because of the declared COVID-19 pandemic [39,40]. At the same time, these months were associated with the moment when weakening the pandemic restrictions in Poland. On the one hand, such situation allowed us to make tests, and on the other hand, the traffic at the airport was very low (according to our measurements carried out at the end of July 2020, there were only 77 vehicles per hour for 38 available parking places in the K&F zone; one vehicle occupied a parking slot for 3 min and 10 s on average), which allowed us to realize the scenario when interactions with other road users were almost excluded and tests could be focused on elements of infrastructure and traffic organisation. Such a situation also neutralized the influence of such parameters like speed, acceleration and deceleration of a vehicle, the waiting time for K&F parking place, etc., making their measurement unnecessary. That is why the study concentrates on standard eye-tracking metrics (number of fixations, duration of fixations, etc.). During the driving tests, there were only two types of weather conditions: sunny or cloudy (no precipitation). Here, it should be noted that the possible influence of sunny conditions will be discussed only when entering/exiting the K&F zone: at this time, the K&F zone itself was in shadow of the terminal building, which eliminated any impact. Importantly, the ethical guidelines set by Politechnika Krakowska and Palacky University Olomouc concerning privacy protection were followed by data processing. After the field test, each participant completed a short questionnaire covering basic demographic data, driving experience, familiarity with Krakow Airport and its surroundings as well as subjective assessments of the route they drove.