Originally Posted by
tusphotog
Occasionally the glass door is open and nobody is around it.
I suspect it has to do with keeping the concourses segregated. If there's a terminal dump in A/B/C, they'd have to dump D and now T3. In other words, the entire airport might have to be emptied out...and that would really, really suck.
So, SEA and other major airports are allowed to have all concourses connected, but LAS isn't. I've always thought that LAS suffers from extremely poor planning. Over the years, LAS has gone through periods where it's bursting at the seams and others, like now, where entire sets of gates are closed or severely underutilized.