A hub-and-spoke network is an airline route system where many smaller cities connect through a few large hub airports. Instead of flying every city pair directly, passengers often travel from a spoke city to a hub, then from the hub to another spoke. This structure matters because it lets airlines serve many destinations with fewer routes.
It also shapes ticket prices, travel times, delays, and airport congestion.
Key Facts
- In a point-to-point network with n cities, the maximum number of direct city-pair routes is n(n - 1)/2.
- In a single-hub network with n cities including 1 hub, the basic number of spoke routes is n - 1.
- A trip in a hub-and-spoke network often has 2 flight legs: origin to hub and hub to destination.
- A connecting bank is a scheduled wave of arrivals followed by a scheduled wave of departures at a hub.
- Total trip time = flight time + connection time + ground time + delay time.
- Hub-and-spoke systems improve load factor by combining passengers from many origins onto fewer flights.
Vocabulary
- Hub
- A hub is a major airport where an airline concentrates arrivals, departures, aircraft, crews, and passenger connections.
- Spoke
- A spoke is a smaller route that connects an outlying city to a hub airport.
- Point-to-point network
- A point-to-point network is a route system where flights operate directly between many city pairs without requiring a central connecting airport.
- Connecting bank
- A connecting bank is a short time window at a hub when many flights arrive and then many flights depart to allow efficient transfers.
- Load factor
- Load factor is the fraction of available seats that are filled by paying passengers on a flight.
Common Mistakes to Avoid
- Counting every hub connection as a direct route is wrong because a passenger itinerary can use two flight legs even when the airline only operates spoke-to-hub routes.
- Assuming hub-and-spoke is always faster is wrong because a connection can add waiting time, taxi time, and delay risk compared with a nonstop point-to-point flight.
- Ignoring connecting banks is wrong because hub schedules are often built around timed waves, not evenly spaced flights throughout the day.
- Comparing only passenger convenience is wrong because airlines also consider aircraft utilization, crew scheduling, gate limits, demand, and load factor.
Practice Questions
- 1 An airline serves 12 cities. If it used a full point-to-point network, how many direct city-pair routes would be possible using n(n - 1)/2?
- 2 An airline serves 12 cities with 1 hub and 11 spoke cities. How many basic spoke routes connect the hub to all other cities, and how many flight legs are needed for a passenger flying between two spoke cities?
- 3 A passenger can choose a nonstop flight or a hub connection. Explain two passenger tradeoffs and two airline tradeoffs that could make either network design a better choice.