I hate traveling. About the only means of transportation that doesn't do terrible things to me physically is walking, which I can do fine in pedestrian-friendly Lawrence, KS but which is impracticable in suburban Kansas City, where many huge, busy intersections don't even have crosswalks. I have never learned to drive, due to a combination of really awful motion sickness making it unpleasant to practice driving and my slow reflexes and inability to multitask* making me a slow learner. Eventually, my ability to tolerate the constant nausea would give out before I got good enough to take the driving test, and my learner's permit would just lapse. (This happened three times).
I had never flown before 2007, when I flew out to Washington DC for ten days to visit my boyfriend. Since then I've done it once more, to get home from The Farm, and am of the opinion that, even though flying is a lot easier on me physically than driving, the mental and emotional strain of navigating airports is about all I can handle --- if something goes wrong, I'm helpless. I am so panic-stricken just from being in the danged airport that the only thought, the only possible course of action I can entertain is to leave immediately. When going home from Washington last year, I was routed through Atlanta, where I missed my actual going-home flight due to a delay. I was already so overloaded that I could not handle standing in line for a new boarding pass; I only wanted to curl up and shiver somewhere. I was able to tell a flight attendant what was happening, and get her to go get a boarding pass for me, and have a guy escort me to my gate. But if she had been less understanding, well, I might still be in the Atlanta airport right now.
(Because of this, I believe the TSA's policy of monitoring the behavior and body language of air travelers is going to net them a whole slew of autistic --- and otherwise invisibly disabled --- "terrorists". Seriously, some of the things they look for --- signs of stress, walking too fast, not making eye contact --- are things I exhibit every time I go out in public.)
Apart from a radical redesign of airports** such that human traffic is directed along lots of smaller corridors to minimize crowding, and getting rid of the cacophany of audible announcements in favor of issuing everybody headsets or a tiny monitor that keeps them posted with information relevant to their flight, I can't think of a lot of recommendations for how to make air travel more autistic-friendly. One quick and easy fix would be more precise training for security personnel about what kind of person (besides a terrorist) is likely to show the cues they're looking for. A few quick questions when they find a potential suspect would then sort out whether the person belongs to one of those categories.
Sadly, since the airlines appear to be hemorrhaging money this year, and high fuel prices are probably here to stay, I think we can rule out any measures that would require any significant investment in improving airports.
*The motion sickness is not related to my being autistic; that, as near as I can tell, comes from my having a series of really bad ear infections in toddlerhood that messed up my inner-ear apparatus, giving me poor balance, tinnitus, high-frequency hearing loss, and the motion sickness and dizziness. The processing difficulties (slower reaction times, lack of multitasking), however, do come from autism.
**The Kansas City airport actually has a decent layout for crowd-minimizing. They have three separate terminals, with security checkpoints at each one, so you only have to deal with a third as many people as would be in an airport of its size. It's not perfect --- that's still more people than I feel comfortable around, and it's still pretty loud --- but it's a step in the right direction.