| This study developed a family of quantitative indicators to measure the systemwide connectivity of the air transportation network by integrating many attributes of routes and schedules in the airline system. Applying this methodology to 1977 and 1984 data for a sample of 27 airport hubs, the changes in connectivity after the Airline Deregulation Act of 1978 was studied.; The connectivity index developed in the study is a ratio between the sum of the reciprocal harmonic mean of the actual trip times, and the sum of the reciprocal harmonic mean of the ideal trip times. The index produces a value between zero and one, one being the best possible airline network connectivity. The measurement of connectivity uses two types of data: (1) flight times including waitings for stops and connections, and (2) frequency of all nonstop, direct and connection flights coming to a destination airport (base) hub from other origin airport hubs. The systemwide connectivity, which is the connectivity between a base airport and all other airport hubs, is calculated by integrating according to some weighting scheme all the group connectivity indices which are categorized by the origin hub size and the distance from the base.; Statistical analyses and comparisons of the mean connectivity and accessibility for the 27 bases show significantly better connectivity in 1984 than in 1977. Connectivity is generally ranked in the order of the base hub size. The systemwide connectivity is the highest for large bases, intermediate for medium bases, and the least for the small bases. Statistically significant interaction exists between base size and origin size. The results also show that for both 1977 and 1984, the differences in the connectivity of large, medium, and small origin size groups are significant.; The study found the concept of connectivity to be meaningful for comparing the quality of network supply. The indicator gives a consistent picture of the quality of airline service and the connectivity in the network structure. It may be used to measure the performance of a network or to evaluate alternative network designs. |
