Flight Time Predictability: Concepts, Metrics, and Impact on Scheduled Block Time

The concept of predictability in air transportation has received increased attention in recent service quality assessments. While in ground transportation the concept of predictability has been extensively studied, there is little literature in air transportation. In this paper, a systematic review of the analogy regarding travel time reliability, or predictability between the two types of transportation is conducted. New concepts of flight predictability and different approaches to measure it at the individual flight level are proposed. The predictability performance of the National Airspace System over the past few years is examined based on predictability measures. It is found that predictability performance has similar trends with traffic volume and flight delay. The time-based metric is further decomposed to see proportion of different contributions. Then, the relationship between flight predictability and scheduled block-time is investigated empirically. Multiple regression models are conducted with the Bureau of Transportation Statistics data. The impact of predictability is incorporated into the models with different approaches. It is found that departure delay plays a minor role in setting scheduled block-time, and that scheduled block times are insensitive to historical flight times in the upper tail of the flight time distribution.