I hope sharing further my differing perspective helps a little.
First off, yes it is hard to be a parent, and is is very hard parenting with special needs children. It can be very rewarding though, so I focus on that.
So, I do see both sides to this parental and ASD issue, as we are parents of Autistic children, and as I am very open minded and will not always agree with parents, but not always with one with Autism either. It depends on the individual circumstances.
From what I see in this thread, the op is not being unreasonable. He seems not lazy, spoiled, and not unreasonable in the things he says. In fact, he seems quite understanding in ways, and with desires to not have disagreements in the home, and with some fairness and empathy shown. That is to be respected.
While I do generally agree that parents should set rules, I do not agree with any parent who has the attitude, “I pay the bills, so do what I say, and care not for what I do.” That is why so many children in this world are abused and neglected, and partly why so many parents are mean. That authoritarian or I’m entitled mindset, as I am your parent and must be bowed down to and respected for everything, as I have the money or am bigger or supposedly wiser than you. To me, such a parent has an unfit attitude.
In this case, apparently the parents made the choice to have children, and to keep going on vacation, so, sorry, my sympathy is not there with parents for any monetary issue, and as the parents could be getting some benefit with that child home. Let’s not assume the parents are burdened by the child. It could be the other way around, and that adult child is trying his best to break free. The father also apparently wanted that vacation destination, and that is fine, if he is paying for it.
But, I do not expect then the child to jump and down in joy and say, “Wow, just what I ever dreamed, to go visit that country and to ride around in taxi, and going where that parent(s) tell I am going, at a moments notice.” If they are not communicating with the child, and do not care about what that child wants for such important family decisions, but dictates, that is not the most wise or caring parent. And a caring parent does not hold dollars bills over their child’s head, to get them to do things only their way.
That is not treating the child like an adult, so for the adult to expect their son or daughter to act that adult way, for all circumstances, when the parent’s are being either childlike, stubborn, not listening, or with selfish intentions, that is not right. Children learn right from wrong from parents. As well, from what I understand, the father broke a promise. That is not showing respect for rules, and it is certainly not mature.
Nor does it necessarily show parental care if saving a little bit of money by not have independent transpiration for the trip is more important than their child’s or adult child’s sensitivities and fears, which could be understandable not only because of the Autism, but because traveling to unfamiliar or new countries can indeed pose extra dangers for that traveler. Cutting costs there by being dependent on public transportation may be putting family safety in jeopardy, and indeed make the experience less enjoyable.
Is there perhaps a better way to prevent disagreements in the family? Yes, BUT then the op would always be doing just what his parents said, and repress his feelings and concerns, feeling anxiety in the process, which will just create more family conflict, if not now, then later. I do not relate to parents like that. We treat our sons as if they have feelings and choices too. We never hold money over their heads, so as to set rigid rules or dictate. We have rules and boundaries, but we always think of the children desires and needs, too.
I trust what any person with Autism says, and do not need a parental side to things, as from my experiences most Autistics are for the most part factual and honest. I have no proof otherwise, and as my first instinct is to support them when they say controlling and stubborn or rigid behavior from parents is involved. Parents are entitled to not being perfect too, but sometimes a parent can resolve a situation by talking calmly things out, and bending if legitimate concerns are addressed.
People assume vacations are fun. Not for all. So, yes, if the op
feels anxiety going on this trip, because of any reason, by all means do not go. You owe your parents nothing there, as apparently you were not in the discussion there, if that was the case. For many persons, trips, and meeting new persons and new places, can be scary even, much less any public transportation. I certainly would not find enjoyment with such a trip.
Like me, many with Autism or other conditions, can be into details and be avoidant of people, or feel different from other people and be hesitant or unable to do certain things. So, if I was in the op’s case, as I am the non confrontational type too, I would not be comfortable with the setup, and would politely decline. Other things the op said about the father bothered me as well. Yes, that parent may need a break from being entirely blamed, but the op certainly is not the main problem here. Please show him support and understanding.