Optimization of the traffic system at the airside of Amsterdam Airport Schiphol

The increased transportation air movements in the past years has raised questions at the department of Airside Operations of Amsterdam Airport Schiphol (AAS) regarding the safety, robustness, reliability and utilization of the airside traffic system. To get more insight to this future situation, the current situation is analyzed first. Rather limited information about the current traffic system was known, besides the fact it consists of the main artery the ‘Rinse-Hofstra road’ and the connecting roads towards the airplane stands. Another observation within the area of AAS is the fact that the research is performed in a complex multi-level actor environment, involving many different stakeholders. Also the variety in vehicles on the airside is very large. The four aforementioned aspects are analyzed in detail and resulted into different improvement possibility proposals. Regarding the safety aspect, several specific analyses are performed; using the black spot methodology, all unilateral and two-sided collisions of the past 8 years are analyzed. This methodology indicated that the main problem areas regarding safety are located at the beginning of the piers. Another analysis estimated an average damage costs of €1612.99 euro per collision, which indicated the fact that a reduction of collisions will directly result in (large) financial savings. Finally, it appears that ‘human errors’ are the most frequent causes for collisions. The second aspect of which the traffic system is analyzed is robustness: “the ability to fulfill the function of which the (traffic) system is designed for, even in non-regular situations which differ (strongly) from regular user conditions“ (Snelder, Immers, & Wilmink, 2004). It appears, using this definition, that the viaducts crossing the A4 highway, the tunnels and the beginning of the piers are not very robust for several reasons; this aspect resulted in mostly infrastructural related improvement possibilities, to make it possible to overtake other vehicles more easily and being able to reroute traffic more easily in case of an accident. The reliability of travel times is the third aspect the traffic system is assessed on, by performing travel time measurements with and without viaducts on the routes. It appears that the F-pier could be reached in the same travel time using the viaducts, coming from the tunnel, although these measurements result in slightly more constant travel times using the ‘viaduct-route’. With the additional proposed improvement possibility of increasing the speed on the viaducts from 30 to 50 km/h, the F-pier can be reached faster by the ‘viaducts-route’ and now the E-pier can be reached in equal time by both routes. Increasing the speed on the viaducts will result in an increased use of the viaducts, which will lead to an increased utilization; this is the fourth aspect in this research. To get more insight in the number of vehicles using the viaducts and other strategic locations within the system, traffic volume measurements are performed by placing three cameras on the airside. It appears that an increased traffic volume of almost 40% of the viaducts can be realized in this way, and so reduction of the same amount on the other route, resulting in an improved utilization. Concluding, a total of 15 different improvement possibilities, with corresponding implementation strategies, are proposed within this research, of which 5 improvement possibilities are resulted as the best improvement possibilities regarding costs, effectiveness (regarding the four aspects) and stakeholder support. These four improvement possibilities are: rerouting traffic over the viaducts to maximize the utilization of the network, increase the cooperation between stakeholders (mostly Airside Support and Airport Authority), add an extra (safety related) training component for new users, remove the current green pedestrian crossings and reduce the number of traffic signs to create a more clear overview.