For the autistic individual, unexpected things often feel very upsetting. Activities that are anticipated, scheduled, and routine are often much more preferred. Indeed, within autism, the brain will lean toward repetition.
One strategy to reduce anxiety in response to daily unexpected events (e.g., schedule changes, construction, car problems) is to create a mini-competition with yourself or others. The goal is to "find at least" one, five, or ten unexpected things during the day and write them down. The amount you choose is completely up to you. In the evening, see if you met your quota and if you were able to "beat" anyone else in your household (or beat your own goal or record).
Instead of running into an unexpected barrier and then feeling overwhelmed, the individual can try saying "Wow. I've already got one unexpected thing on my list! That was fast. I wonder if I'm the first one in my family to get one."
Of course, this one strategy doesn't make it easy to encounter surprises during the day. But it may be one of many strategies that can help take the edge off of dealing with change and obstacles in daily life.