pronounced "spesh-ee-al-it-tee"...
been there, done that, made it therapeutic!
I wonder if my old post about Theme Park Therapy is still around... I'll look. There are lots of ways to keep things safe and sane -
1) Just say no to Commando/Turbo Touring. SLow, easy, repetitive, calm, gentle -- oh, that is YOU, the parent, not the rides by the way! You have to use your own emotional and physical homeostasis to help your kid feel safe and grounded. Actually getting on a ride is totally optional, unless you are in the process of doing Theme Park Therapy (my own home-made brand of progressive desensitization technique)
2) Use a sturdy smooth-rolling stroller. One with sides and a cover would be nice- the deep pressure and containment help them feel more safe.
3) Reduce auditory input as much as possible, remember that they rely more often on their visual for cues.
4) When they are acting out, try to remember their reduced verbal abilities and hypersensitivity to physical stimuli... at all costs, avoid getting tense, uptight or punitive!!!! That squirrely behavior may be a sign that there is a little blister that you can hardly see that is causing them total overload, or a bit of a sunburn that most kids would brush off that makes them totally miserable, or somebody else's tension and frustration are causing them emotional distress.
5. 3 years old is still young... with proper support they do learn to love it! But some people have one little disaster and then avoid theme parks altogether from then on - big mistake! Imagine what it will be like if all their friends go out to a fair one day when they are older, but your kid can't go because she never learned how to cope with the sensory input... a major social loss for kids with special needs if they can't go on trips with their pals.
6) Mental Preparation is very helpful! Trip planning videos, sing-along videos that feature the parks, books about the parks, about the characters, about circuses and fairs... and lots of trips to smaller parks closer to home - short, repetitive, predictable trips loaded with fun - a great way to prepare.
I am sure other people have some good ideas...