Ironically, that marked vest may cause more harm that good. I would think that motorists would have to be very close to read it; maybe part-way through the pass. It would be a good experiment to try with a plain bright green vest and see if you notice a difference.
There are bumper stickers in the USA with too much text on them, and it causes other motorists to tailgate them just to read, so it actually causes a problem.
{Off-topic} Re. your "Autistic and Happy" signature, I've that autistic people I've known and met usually have a "superpower" to help compensate for the social issues. Do you have an "autistic super power?"
One family friend seems to have a photographic memory for train statistics and routes. Super-nice boy. His sister has more mild autism but can be very nasty and antisocial, but she's already in college engineering classes in high school. Another autistic boy I met in a hotel pool could do amazing math in his head. (if you don't want to talk about it publicly, I understand, no need to respond)