Document Type


Date of Degree Completion

Spring 2023

Degree Name

Master of Science (MS)


Cultural and Environmental Resource Management

Committee Chair

John T. Bowen Jr.

Second Committee Member

Toni Sipic

Third Committee Member

Pere Suau-Sanchez


The purpose of this research was to define, map, and quantify the network and environmental implications of “long-thin” routes (LTRs) – a route structure that has been discussed in the aviation industry but not formally studied in literature. LTRs were defined through the use of global OAG scheduling data from 1998 to 2018 to identify trends in air traffic growth and network dynamics. Flights were separated into seven aircraft class sizes (e.g., 75–150 seats, 150–225 seats) to measure LTRs at multiple scales. Routes were considered “long” if the stage length was at or above the 75th percentile in each class size and considered “thin” if the total seats of each airport-pair vv (visa-versa) was at or below the 25th percentile for the size class. The overall share of LTRs across the study period rose from 1.59% of total seats in 1998 to 2.24% in 2018. While LTRs comprise a small share and may be considered “niche” by some, their global coverage shows they play an integrating role, as about a third of airports were linked by at least one LTR over the study period. LTRs account for a disproportionately high share of CO2 emissions relative to their share of total seats but are more efficient than non-LTRs on an available seat-nautical mile basis. In addition, the share of LTRs within regions that implemented a carbon policy was found to rise significantly, though the coverage of such policies remains sparse. Overall, this research presents an original definition of LTRs and situates them in the rivalry between low-cost carriers and other airlines, along with the airline industry’s contribution to climate change.