The form of the passenger terminal building is shaped by many influences. Available real estate, budgetary constraints and the size of aircraft servicing the terminal all contribute to the eventual geometrical layout of the building. In addition to these factors, the physical architecture of the terminal building is also heavily constrained, or influenced, by the business logic surrounding passenger processing. These logical/business processes are directly reflected in the layout of the terminal building. An excellent example of this can be found in the stairwells of Zurich International Airport (ZRH).
Following Switzerland joining the Schengen countries in 2009, ZRH underwent a major expansion and refurbishment project. A key focus of the project was to make accommodations for the processing of Schengen and non-Schengen passengers.
Passengers arriving at ZRH may have begun their trip in either a Schengen or a non-Schengen country. On deplaning at ZRH, passengers could be terminating in Zurich (Schengen), or transiting to another airport (either Schengen or a non-Schengen). Of the transit passengers, those travelling to a “One Stop Security” (OSS) destination need not have the in-transit security check.
Logically, this gives rise to five possible scenarios for processing arriving passengers, namely (Figure 1):
- Schengen to Schengen
- Schengen to non-Schengen
- Non-Schengen to Schengen
- Non-Schengen to non-Schengen (OSS)
- Non-Schengen to non-Schengen (non-OSS)
Each of the above processing scenarios is associated with different immigration (visa) and security requirements. Hence, the arrivals process would differ depending on which of the above scenarios held for a given passenger, i.e.:
- Schengen to Schengen: no visa or additional security check required.
- Schengen to non-Schengen: visa check required, no additional security check required.
- Non-Schengen to Schengen: visa check and additional security check required.
- Non-Schengen to non-Schengen (OSS): no visa check and no additional security check required.
- Non-Schengen to non-Schengen (non-OSS): no visa check but additional security check required.
In order to facilitate the correct routing of passengers arriving at ZRH, the airport commissioned the construction of specialized stairwells linking the skybridge to the terminal building. The stairwells are equipped with physical switches to route arriving passengers down the correct processing path (marked as “doors” in the figure above. For example, passengers arriving from Schengen countries and terminating their trip at ZRH (scenario one above) would proceed down the path which had the immigration pathway closed (as not required) as well as the additional security pathway closed (again, as not required).
The elaborate design, construction and operation of these stairwells mirrors the complexity associated with the underlying processing logic. It follows therefore, that any simplification of this logic would likely result in a direct simplification (and thus cost reduction) associated with the architecture of the corresponding physical structures.
Source: sincere thanks to Pawel Kolatorski, formerly of Zurich International Airport, for his collaboration and insights.