What is a common feature of O'Hare's airport layout?

The common feature of O'Hare's airport layout is the linear terminal concourses. This design allows for an efficient flow of passenger traffic between the terminals and concourses, facilitating easy movement to and from gates. The linear arrangement typically supports a clear line of sight for passengers navigating the airport, enhancing accessibility to amenities and services.

In contrast to other options, the circular terminal structure is not characteristic of O'Hare; instead, the layout is defined by long, linear terminal concourses connecting to the central terminal area. Multiple parking levels, while present, do not define the airport’s layout but rather serve as support infrastructure for passenger access. A single terminal configuration is also not applicable since O'Hare operates multiple terminals, each with its individual concourses, emphasizing the complexity and size of the airport compared to a single terminal setup.