## 1 Introduction  
One of the most significant factors causing runway excursions is poor braking performance. Loss of control on the runway accounted for 15.5% of all the aviation accidents that occurred between 2010 and 2019 [1]. In 2019 alone, those accidents cost the air transportation industry $4B directly. Most of the accidents occur during winter since the runway is contaminated by snow, slush, ice, brine or water, rendering the surfaces slippery [2]. They all have a negative effect on braking performance, significantly reducing the friction between aircraft fires and the runway surface, inhibiting maneuverability [1, 2, 3, 4, 5, 6, 7]. Different methods exist in the literature to evaluate braking performance based on the state of the surface. Most of these are American Society for Testing and Materials (ASTM, West Conshohocken, PA, USA) standards used to measure the surface friction characteristics. These tests can be divided in four classes: (i) fixed tests, (ii) braking tests, (iii) contact tests, and (iv) non-contact tests. Fixed tests are the most popular. There are a few apparatuses which allow the friction between the tire and runway to be measured directly. These apparatus are capable of performing lateral force tests (ASTM E670) [8], fixed slip tests (ASTM E2340) [9], and locked wheel tests (ASTM E274) [10]. They all work following the same principle where a host vehicle drags a tribometer (here, a tire) maintaining a constant speed, thus allowing the friction and load force to be measured. The friction coefficient is then determined using the ratio of the friction and load forces. The second class of tests consists of braking tests which are done by: (i) measuring the stopping distance (ASTM E445) [11], or (ii) measuring the deceleration rate (ASTM E2101) [12]. The stopping distance measurement is conducted by displacing a vehicle at 65 km/h on a contaminated road followed by locking of the wheels. The distance d is then measured until the point where the vehicle comes to a complete stop and the friction coefficient is then determined. The greater the distance, the lower the friction coefficient will be. In measuring the deceleration rate, on the other hand, a vehicle is displaced at a speed between 32 and 48 km/h followed by locking of the wheels to determine the deceleration. The friction coefficient is then calculated as a function of the difference between the initial and final speed. The greater the difference, the higher the friction coefficient will be. The application of the two latter classes is aimed at real-life operational cases and may not be considered for a laboratory test. The third class consists of the contact tests. They are those tests which imply contact with a limited part of the runway. Contrarily to the other two classes, these tests could be easily performed under laboratory conditions, as well as in natural outdoor operational conditions. The main apparatus in this category is the British Pendulum Tester (BPT, ASTM E303) [13]. The BPT is a dynamic test which works on the principle of the Sharpy test, whereby a rubber slider in contact with the surface allows for skid evaluation. The British Pendulum Tester allows for the evaluation of surface texture. The greater the surface roughness, the greater the difference will be. The result is given as the British Pendulum Number. More recently, non-contact tests have been proposed to the industry: (i) electro-optic test, and (ii) the circular texture meter (ASTM E2157) [14]. The electro-optic test measures the pavement texture properties at high-speed, using ultra high-frequency laser triangulation mounted on a car. On the other hand, the circular texture meter is used at a fixed position with a laser-displacement sensor. With this method, the surface macrotexture is determined using the calculated roughness parameters.