How do pandemics affect intercity air travel? Implications for traffic and environment

This paper investigates how a pandemic affects the distribution of traffic between public and private transport and the emissions from the transport sector. By assuming that there exists higher health risk of traveling in public transport than in private transport and using air transport and private cars as examples, we find the following results. First, the effects of a pandemic on the traffic volumes of airline services and private cars depend crucially on, for instance, the willingness-to-pay of travelers, the degree of substitution between transport modes, the demand-side network effect (via schedule delays), and the supply-side network effect (via the economies of traffic density). In particular, heterogeneous effects of the pandemic on the traffic volumes and flight frequencies of different airline services are found. Second, the total transport-related CO2 emissions decrease after the pandemic if the CO2 emissions per air traveler (or per flight) are sufficiently high, or the degree of substitution between airline services and private cars is sufficiently low. Third, numerical examples on the change in price of car travel and the introduction of high-speed rail show consistent insights. Finally, several policy implications are discussed.