Impact of Shared E-scooter Introduction on Public Transport Demand: A Case Study in Santiago, Chile

TL;DR

This study investigates how shared e-scooters influence public transport demand in Santiago, Chile, revealing that e-scooters can both substitute and complement transit depending on the urban region, with implications for mobility policy.

Contribution

It provides empirical evidence on the spatially heterogeneous effects of e-scooters on public transport demand using detailed smart card and GPS data in Santiago.

Findings

E-scooters reduce public transport use in high-density areas by 23.87%.

E-scooters increase transit ridership in intermediate regions by 33.6%.

Peripheral regions show no significant impact.

Abstract

This study examines how the introduction of shared electric scooters (e-scooters) affects public transport demand in Santiago, Chile, analyzing whether they complement or substitute for existing transit services. We used smart card data from the integrated public transport system of Santiago and GPS traces from e-scooter trips during the initial deployment period. We employed a difference-in-differences approach with negative binomial regression models across three urban regions identified through k-means clustering: Central, Intermediate, and Peripheral. Results reveal spatially heterogeneous effects on public transport boardings and alightings. In the Central Region, e-scooter introduction was associated with significant substitution effects, showing a 23.87% reduction in combined bus and metro boardings, suggesting e-scooters replace short public transport trips in high-density areas. The Intermediate Region showed strong complementary effects, with a 33.6% increase in public transport boardings and 4.08% increase in alightings, indicating e-scooters successfully serve as first/last-mile connectors that enhance transit accessibility. The Peripheral Region exhibited no significant effects. Metro services experienced stronger impacts than bus services, with metro boardings increasing 9.77\% in the Intermediate Region. Our findings advance understanding of micromobility-transit interactions by demonstrating that both substitution and complementarity can coexist within the same urban system, depending on local accessibility conditions. These results highlight the need for spatially differentiated mobility policies that recognize e-scooters' variable roles across urban environments.