Every day after work I walk to a designated location and wait in a long line of people while cars drive by and pick us up so they can use the carpool lane: it’s called the Slug Line.
A couple of months ago I was curious as to when was the optimal time to arrive at the slug line. Inspired by the exhortation at the end of Atul Gawande’s excellent Better and the enthusiasm throughout Ian Ayer’s, well, extremely enthusiastic Super Crunchers, I started collecting data.
I still don’t have enough data to give me an optimal arrival time. BUT if a run a simple regression of the time it takes to get a car on the number of people in front of me in line, I get a highly significant prediction: each extra person adds about 30 seconds to my wait. For the last week, this has predicted my wait time almost exactly.
It’s refreshing to see a pattern in something – like so many – that appears completely unpredictable at the outset. And now I can tell my wife when I’ll be home.
David Evans' personal blog 