@Elanetical
"I have spent a lifetime being told I'm rude for being late, and NOT having people consider that there are reasons for lateness that are unavoidable."
There are no reasons that are unavoidable. None at all. They just need to be overcome. Most people who are consistently late don't consist themselves late until the time that they should be somewhere has passed. They forget that they have to travel, perhaps park, walk to the venue, pay for entrance, find the person they are meeting, etc., and that all takes time.
If you want to be on time, you need to work backwards. Set the time you want to be at the place you need to be and ready to do the activity you are going to do, then allocate time to each step of the process that will allow you to achieve that. That will give you your timeline.
Example:
I start work at 8pm on a night shift, but I like to get a parking place, have a casual walk up to the unit, get into the unit and see what patients we have, how the day shift have got on, which patient I'm allocated, and have a cup of tea before the shift handover. So:
8pm: handover
7:50: cup of tea
7:45: in to handover room
7:35: arrive on unit
7:30: walk to unit
7:25: park
7:00: leave for work
6:45: dry hair
6:30: prep uniform with equipment/get dressed
6:15: wash/shower/wash hair
6:00: eat dinner
So if I want to be ready and do all the things I like to do before I start work, I have to start getting ready at 6pm, and leave the house at 7pm. Crucially, my timeline has enough slack that if something goes wrong, I can skip the casual stroll to the unit, the chat and the cuppa, and I know that really, as long as I leave the house by 7:30, I'd have to run, but I'd still make it to work on time.