Ride-sharing, congestion, departure-time and mode choices: A social optimum perspective

2025 Ghoslya, Samarth and Javaudin, Lucas and de Palma, André and Delle Site, Paolo

Abstract

In densely populated urban areas, increasing private vehicle usage continues to overwhelm existing transport infrastructure. Peer-to-peer ride-sharing—where drivers are also travelers—offers a promising solution by shifting mobility from ownership to usage. However, the real-world effects of ride-sharing on urban networks depend on dynamic travel behavior, network congestion, and operational constraints. We introduce a novel ride-sharing scheme that minimizes total social costs—including travel time, emissions, and fuel consumption—within a dynamic, multi-modal transport framework. The proposed method integrates a linear matching optimization with the agent-based simulator METROPOLIS2 to jointly model route, mode, and departure time choices under endogenous congestion. When applied to the Île-de-France region during the morning peak, the socially optimal matching scheme results in 4.0% of trips using ride-sharing, reducing vehicle kilometers by 5.8% and daily CO2 emissions by 342 tonnes. These results demonstrate the potential of ride-sharing to generate substantial environmental and efficiency gains, particularly when supported by targeted incentives.

Keywords

Dynamic congestion; Environment; Large-scale optimization; Ride-sharing; Socially optimal matching

Bibtex (click to select)

@unpublished{GhoslyaEtAl2025,
  author  = {Ghoslya, Samarth and Javaudin, Lucas and de Palma, André and Delle Site, Paolo},
  title   = {{Ride-sharing, congestion, departure-time and mode choices: A social optimum perspective}},
  year    = 2025,
  month   = 09,
  doi     = {https://dx.doi.org/10.2139/ssrn.5465467},
}