CHICAGO—As Amazon considers possible locations for its HQ2, a second headquarters facility that will match and complement the firm's Seattle hub, cities across North America are scrambling to put together proposals. Most experts believe Chicago has a good shot, and may even be on a short list that excludes the vast majority of cities making the attempt. But dark horse candidates also exist.

“Atlanta could surprise us,” Deena Zimmerman, vice president in the SVN Chicago office, tells GlobeSt.com, “primarily due to its great transportation infrastructure.” The city's airport usually vies with Chicago's O'Hare for the title of nation's busiest. And Amazon wants a place where it can “quickly can get their people in and out.”

That's a key consideration for a headquarters expected to encompass millions of square feet and host up to 50,000 people, but Zimmerman is skeptical that any cities can match Chicago. It has two major airports connected to the downtown by subway trains, and that provides an advantage over rivals when it comes to transportation. And the city is also superior in other important aspects.