Enhancing private transportation: The positive spillovers from Santiago's subway expansion

In Latin America, where traffic congestion is severe, governments often expand subway systems to reduce traffic. Evaluation of the efficacy of these investments poses challenges, notably due to the scarcity of real-time data. This study uses Uber Movement data, which provides detailed information on daily travel times, to examine the effects of subway expansions on car transportation in Santiago, Chile. We find that introducing a new subway line reduces car travel times by an average of 1.5% (0.309 min), with a greater reduction of up to 0.571 min during peak traffic hours.