Benefits of Shifting Passenger Traffic from Air to Rail: A Case Study of California High-Speed Rail

2026-08-06

AI Summary

This study quantifies the indirect cost savings from flight delay reductions attributable to air travelers shifting to high-speed rail. Drawing on passenger flow projections from California’s 2020 High-Speed Rail Business Plan, the analysis simulates airline capacity reductions and allocates them across 15-minute time intervals. Using a Lasso regression model, it evaluates how reduced queuing delays at San Francisco, Los Angeles, and San Diego airports propagate to arrival delays across 29 major U.S. airports, monetizing the resulting time savings. The research pioneers the integration of high-speed rail demand forecasts with a nationwide airport delay propagation framework to systematically assess the macroeconomic benefits of intermodal substitution. Findings indicate that flight delay cost savings will reach $51–88 million in 2029 and $235–392 million in 2033 (in 2018 U.S. dollars).

Abstract

This study provides a method to quantify the benefits of shifting passenger traffic from air to high-speed rail from the perspective of flight-delay cost reduction. We first estimate the number of flight reductions for airport origin-destination pairs based on the high-speed rail ridership forecasts provided in the California High-Speed Rail 2020 Business Plan, and then distribute these flight reductions to quarter-hour intervals. Lasso models are applied to estimate the impact of reduced queuing delays at SFO, LAX, and SAN on arrival delays at the national Core 29 airports. These delay reductions are then monetized using aircraft operating costs and the value of passenger time. We evaluate alternative airport-capacity and flight-schedule scenarios, as well as multiple percentiles of probabilistic high-speed rail ridership forecasts. The resulting estimates indicate flight-delay cost savings of $51-88 million in 2018 dollars in 2029 and $235-392 million in 2018 dollars in 2033.

Problem

• flight-delay cost
• high-speed rail
• passenger traffic shift
• airport congestion
• delay reduction

Innovation

• flight-delay cost reduction
• high-speed rail ridership
• Lasso regression
• queuing delay estimation
• monetization of time savings