Even in Kyoto

The rule-of-thumb about transit travel times (between two and five times driving time) was repeated often by my transportation professors when I was in grad school, and I can attest to its subjective reliability in my experience in the years since then.

Regarding a PTI for public transit -- buses also get stuck in congestion, they run late, and sometimes don't show up at all, so a person does need to allocate time in addition to the time one would calculate from the published timetable. I suspect that a transit PTI would vary from city to city, from transit agency to transit agency, due to on-the-ground circumstances and how the agency is managed.

Also in my experience, I pretty much need to budget zero additional time for trips on foot or by bicycle -- there is simply no congestion affecting these ways of travel, though I do occasionally experience a delay due to a construction project, or a bridge opening.

Love,
Dad