Savings in per-passenger CO₂ emissions using rail rather than air travel in the northeastern U.S

Individuals and institutions seeking to reduce travel-related carbon dioxide (CO₂) emissions by changing travel modes need information on the amount of CO₂ that can be saved by rail travel rather than air travel. This study uses flight emissions data from the International Civil Aviation Organization (ICAO) to estimate average per-passenger CO₂ emissions saved by using rail travel between selected city pairs in the northeastern U.S. Trend lines are developed from the ICAO data for different aircraft types to facilitate comparison with CO₂ emissions from rail travel. Separate rail emission factors are calculated for portions of Amtrak's system operating electric and diesel locomotives. An adjustment factor is estimated to account for longer rail distances than flight distances. Results show rail travel has generally lower CO₂ emissions than air travel, with substantially lower emissions for electrified segments of the Amtrak system. At flight distances of over 700 miles, air travel using single-aisle jets can have lower per-passenger CO₂ emissions compared to diesel-powered rail travel, accounting for the longer distances by rail.Implications: Savings in per-passenger CO₂ emissions using rail rather than air travel in the northeastern U.S. Travel by rail in the northeastern U.S. results in lower CO₂ emissions compared to travel by air between the same city pairs using existing airline and passenger rail infrastructure. Savings are higher for cities connected by electrified rail.