Has this "straight through" airport design ever been contemplated? Here's an airport, with some planes on the various runways/taxiways and some using the terminal ..

(airliners in green)



Airport/terminal design is really tricky.

There are many spatial problems which are unsolved, resulting in the incredibly inconvenient (for humans/planes) current airport paradigm.

Has an "over" terminal ever been contemplated?



terminal indicated in blue



So, the (whole) airport terminal building is simply up on stilts.

(Obviously, the clearance is high enough for the tallest existing and forseeable airliners.)

At a stroke this utterly solves two problems:


Airliners never again need to reverse.  They just land, drive around anywhere they want, stop under the terminal.  Passengers get on and off.  The airliner drives off again, drives to a runway (perhaps again passing under the terminal - no issue) and flies off.


No craft would ever reverse.

This would be a complete paradigm shift, slashing handling times, costs,  personnel, machinery.


The fundamental spatial problem of airports is solved at a stroke: You can land or take off anywhere, and get to and from, any gate.  (Sure, you have to avoid the few pillars holding up the terminal.)
From the human crowd movement viewpoint, the need for the hell of "separate terminals" is slashed or even eliminated. At worst you'd just have two or three "ranks" of these (rather like giant rows of car parking in a parking lot).


Again this would spectacularly slash the size and infrastructure costs of airport concept design. Often the whole concept of ridiculous people movers, monorails etc would be eliminated or slashed.

Note that the car freeway system would just connect to the end(s) of the terminal building. (Indeed, as usual.)

(But indeed, perhaps the blue structure could indeed include "the road itself". So the blue object represents both car driving lanes and the terminal structure, shopping, etc.)

On that: looking ahead, it's possible there could finally be a drive to your actual gate concept (if check-in / baggage handling / border functions could be rationalized), which would be an total paradigm shift in air travel.

The only technical difficulty is AeroTech or whoever would have to make a jetway that comes "down"...





Note that it's obviously trivial to make huge civil structures "elevated",



(Indeed a civil structure for foot traffic, shops, etc is (I believe) a lighter load than a super-freeway or bridge,


)

Ideally the supporting piers would be infrequent, allowing for totally free and easy movement of airliners, but even if the columns were between each "bay" the major paradigm shifts are achieved.

This airport paradigm would seem to be staggeringly more efficient than the current paradigm.  No reversing ever!  Free driving anywhere for all craft over the entire area.  Wasted space slashed.

Has this ever been contemplated?
Yes. An architect named Miklos Deri seems to have contemplated something similar: Drive Through Airport – Inversion of Procedures. The design is based around smaller aircraft (which reduces some of the height and size problems) and stacks aircraft together in lines to address the space efficiency issues. 

Nobody has built such an airport (it's a concept, not created for any particular project), and there are practical problems associated with moving aircraft multiple times during a turnaround.