Originally Posted by
JimInOhio
An airside tunnel can't replace the ATS for a couple reasons: You can't practically do security screening at T5 for all INTL arrivals making connections (not to mention walking to T1 is way too far) and without the ATS, you can't rent a car at O'Hare.
Sorry if I wasn't clear, I meant no need for
airside ATS which is what the post I was responding to was wishing for: "ORD building an airside ATS connection between T1/2/3 and T5 would have been nice."
I'm guessing a tunnel would be cheaper than a new airside ATS system and would provide a good link for people who don't mind walking since T3 and T5 are not that far apart physically and TTB is almost certain to be eliminated when new T2 opens.
Obviously landside ATS serves a number of roles including connecting people to airport hotel, economy parking, rental car, transit, etc. that could not be replaced by a tunnel or walkway because of the distances involved.