## 6 Conclusions  
The aim of the research was to widen the knowledge on the potential of applications using AR technology in the DGA process in airports. It was expected that the support provided by applications, could make the work of a DG operator easier and, in this way, could increase the safety of the DG transport as well as the efficiency of the process. The experiments in laboratory and operational conditions have let one draw conclusions on whether expected assumptions can be confirmed and which level of AR immersion reveals the greatest potential. Summarizing, the potential for AR support in the DGA process is very positively assessed by experts; however, there are differences between areas which indicate the most promising and less promising elements. The results of the survey among DG operators have proven that they especially appreciate the augmented reality given by AR goggles when its goal is to show/indicate virtual pictures of data and related law regulations in regard to controlled DG shipments. Thanks to the automatic identification of the shipment, the data can easily be strictly joined with the shipment. This identification reduces the probability of mistakes and the time devoted to data acquisition. On the other hand, when operators are to interact with the augmented reality (e.g., confirm a task in AR goggles), this interaction is assessed less positively. Operators indicate that, for an unexperienced person, such usage interactions are not very easy and that long work conducted through AR goggles is more tiring than using AR support offered by a smartphone. The tiredness effect is similar to what was reported in the literature (e.g., [25]) and could be treated as an argument against the excessive usage of AR goggles in the DGA process. The results of the study can also be considered as initial premises which let one evaluate the potential of full DGA automation. Using the conclusions from the research, it should be noted that, at the present stage of IT development, AR solutions can effectively support the process carried out by an operator during the DGA process after specialist training, but the process should not be automatized because the reliability provided by the applications is too low in some cases. Finally, operators have decided that--from their perspective--they prefer using the smartphone application, which has more limited AR possibilities in comparison to AR goggles but is more convenient in regards to interaction and offers longer work periods. Undeniably, AR technology could be a very effective source of improvements in processes where the removal of human worker is impossible, like in the case of the DGA process. The results obtained in the study let one indicate directions for future research, e.g., it would be worth examining whether the quality of different AR goggles can improve operators' impressions when they interact with goggles. It would also be interesting to learn whether longer experience with AR googles could change the operators' opinion about the easiness of AR interactions. The presented results are limited in regard to the quantitative evaluation of possible improvements of the DGA process. For this reason, long-term research should be conducted to learn what level of time and reliability improvement could be achieved with AR support. Another important limitation of this study is the limited number of operators who had the opportunity to test both applications. In the future, the study results should be confirmed by an increased number of potential users from other airports. However, with these initial conclusions from the study, the next piece of research (including larger operators sample and more quantitative evaluation) could be extended and a third form of AR tool could also be tested, e.g., a tablet application.