Suggests people think of their commute as 20 plus a few minutes but rounding down optimistically, or think of it as almost 30 minutes rounding up angrily, never think of it as 27 minutes.
No writeup of the commute data has mentioned this phenomenon, which I suspect was exactly the same thinking you describe.
https://www.census.gov/content/dam/Census/library/publicatio...
15 to 19 minutes . . . 14.9%
20 to 24 minutes . . . 14.1%
25 to 29 minutes . . . 6.6%
30 to 34 minutes . . . 13.9%
// Noticed this while researching for a comment on HN a few weeks back.
Unless you're talking to a child who has not yet internalized this distinction! My kid frequently asks exactly how much time has passed, and I sometimes have to explain that I don't mean five minutes literally, but figuratively.
They just round more than you: I think your presumption that others should think like you is bizarre. Some people only round to 10 cents. If you are wealthy enough, you could easily round 10.99 to $0.
What I actually wrote was "bizarre to me", not just "bizarre" (as in your quote), so I don't think it's fair to say that my comment conveyed such presumption
But I live in a very dense city (Chicago), it’s become almost “set your watch to it” reliable that not only are estimates more reliable from friends who live here when they say “I’ll be there in 8 minutes”, they’re also seemingly more likely to offer such a precise estimate because they know the area, light timings, and traffic patterns and that certain kind of behavior found among drivers in this city.
Compared to when I have friends from out of town renting a car they’ll tell me “GPS says we’ll be there in 10 minutes” I instinctively add another 10 and it’s never failed that they’ll show up and go “that was a long 10 minutes!” And I just smile.
It was practically a given that the first time someone visited they would arrive 15-20 minutes later than they estimated. It seemed like an area without a lot of traffic but it was in that uncanny valley where there’s enough traffic where you catch a lot of lights, and you aren’t turning right on red because there are people in front of you, and you may or may not make the left turn light on the first cycle.
Also the whole city is so tuned for one direction of traffic that it takes longer to go across the narrow dimension than the long one.
There was a movie theater that I found I could reliably get to faster on a Friday evening if I drove five blocks past it and doubled back, the lights were that screwed up. 15 blocks faster than 5.
This is really impressive, this works each time. Especially if you are on ski slopes and you have two groups trying to meet at a given point. 10 minutes == "We can do another run or two". 8 minutes == "We need to pay attention, they are coming right now!"