# Modelling of Evenness of Runways as an Element of Sustainable Airport Maintenance
## 1 Introduction  
The sustainable maintenance of airport runways has a significant impact on ensuring the safety and efficiency of airport operations. The first objective to be pursued is that airports, regardless of their size and volume of passenger and cargo traffic, should be operated. During operation, the airport's entire transport and support infrastructure must meet all known safety standards. Airports with all relevant infrastructure and services are complex entities with highly demanding management. Air traffic effectiveness is achieved through the provision of highly efficient airport services and a modern and well-maintained airport infrastructure. Efficient airport management requires a large amount of data on the structure and condition of airport facilities, airport operations, and the airport environment. This data must be up-to-date, accurate, and available to airport personnel at all times. Although it is possible to obtain this data manually, based on predefined protocols, this is a time-consuming activity that is also a source of human error. Alternatively, the data can be obtained andprocessed by automated procedures that are part of existing information systems or those that are being developed. The requirements for such systems--timeliness, accuracy, and continuous availability--encourage system development to enable automated acquisition in real time [1; 2; 3]. Sustainable runway maintenance at airports means that a complete and comprehensive management system must be in place, must involve all key decision-making levels, and must ensure that all key processes and systems must be in place to enable sustainable control and action, taking into account all internal and external influences [4]. In general, logistic systems only function effectively and successfully when all corresponding elements function effectively and successfully. If one element of this chain is not effective and successful, the logistics system is inefficient and will not achieve its goals [5]. The quality of the logistics infrastructure is one of the most important means to strengthen international competition and expand the market share of enterprises [6]. The general opinion is that transportation logistics is vulnerable and open to many global business threats. For example, accidents and political conflicts can cause market disruptions. Infrastructure constraints or blockages can also prevent the basic objectives of the logistics system from being achieved. [PERSON] et al. [7] concluded in their study that inappropriate and inadequate logistics infrastructure is the second most important factor for inefficient logistics. [PERSON] et al. [5] propose a directional model for the case of accidents or disruptions that limit the function of logistics infrastructure. Air transport plays an important role in the world economy and is also a reason to ensure proper maintenance of airport infrastructure [8]. This was directly proven by [9] who emphasized that improving airport infrastructure can reduce the cost of air transport by up to 15%, which is a significant part of logistics costs. For this reason, it is necessary to ensure that the operations in the process of airport infrastructure maintenance are carried out rationally. This will ensure that maintenance costs are kept to a minimum and that airport closure time due to maintenance is kept to a minimum. The evenness of an airport runway is one of the most important characteristics of man-made structures for the taxiing phase and landing of civil aircraft [10]. Passengers can subjectively judge the flatness of the runway by the presence or absence of vibrations during the movement of the aircraft on the runway, both during the taxiing phase and landing. In addition to the subjective comfort of passengers, it is worth noting that vibration due to unevenness can affect the structural stability of aircraft and that unevenness (particularly larger areas of unevenness-depressions) of the runway are those places where water can be present for extended periods of time.