i'd like to know the variance of the two looks like, and how much earlier transit riders have to leave wherever they are to account for it, than drivers. (this

i'd like to know the variance of the two looks like, and how much earlier transit riders have to leave wherever they are to account for it, than drivers. (this wouldn't show up because they measured door-to-door times.) admittedly i'm able to keep my car in good repair, but: over the decades i've only had a handful of days where my car didn't start in the morning, or i encountered _unexpected_ events on the road that made the trip take dramatically longer. (heavy traffic on a road i use every day would just show up in my average.) but when i've tried to use buses, while in school, or a brief period when my employer was at the other end of the bus that stopped in my neighborhood, i had buses not show up about once a week (or show up well ahead of the posted schedule). now that i think about it, i've been on about as many buses that had traffic accidents as i've had days where my car didn't start, despite using my car 100x more often than i've taken a bus.