What defines a 'Depressed Roadway' at O'Hare?

A 'Depressed Roadway' at O'Hare is specifically defined as a road that is located between terminals and is lower than the aircraft gate areas. This design allows for the seamless movement of vehicles while minimizing the interaction between road traffic and aircraft operations. Essentially, the depressed position of the roadway is intended to enhance safety and efficiency by separating ground vehicles from aircraft movements, ensuring that there is less risk of accidents and disruptions.

The other options do not accurately capture the specific characteristics of a depressed roadway at O'Hare. For instance, a roadway being elevated above aircraft gates or one that is designated for baggage pickup only does not align with the function and definition of a depressed roadway. Additionally, a roadway with no traffic does not reflect the active use and operational needs typical of a depressed roadway structure at an airport. Thus, the key factor defining a depressed roadway is its relationship to the terminal and aircraft gate elevations.