More time on the plane, but more flights arriving early

By just about every metric, flights are slower now than they were 30 years ago. However, the percentage of flights that arrive early is higher, based on an analysis by Ben Blatt for NYT’s Upshot.

Why do today’s flights arrive early more often, even though they’re slower? Airlines have extended their scheduled flight durations even more than the flights have lengthened in actual duration. The average scheduled duration from J.F.K. to Los Angeles has increased 23 minutes since 1995, according to an Upshot analysis of Bureau of Transportation Statistics data.

Publish a metric that involves money, and companies optimize for it somehow. In this case, the airlines lowered expectations to create a buffer.