# Fair Transit Stop Placement: A Clustering Perspective and Beyond

arXiv: https://arxiv.org/abs/2602.06776 · HTML: https://mlsanity.com/paper/2602.06776/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- Builds on 16 of its 38 references that are in the map.
- First posted on arXiv 6 Feb 2026.

## Builds on (most cited first, 16 of 16)

- [Proportionally Fair Clustering](https://mlsanity.com/paper/1905.03674/) (2019)
- [Justified Representation in Approval-Based Committee Voting](https://mlsanity.com/paper/1407.8269/) (2014)
- [Multi-Winner Voting with Approval Preferences](https://mlsanity.com/paper/2007.01795/) (2020)
- [Fairness in Federated Learning via Core-Stability](https://mlsanity.com/paper/2211.02091/) (2022)
- [Fair Allocation of Indivisible Public Goods](https://mlsanity.com/paper/1805.03164/) (2018)
- [The Core of the Participatory Budgeting Problem](https://mlsanity.com/paper/1610.03474/) (2016)
- [Fair mixing: the case of dichotomous preferences](https://mlsanity.com/paper/1712.02542/) (2017)
- [Proportional Fairness in Clustering: A Social Choice Perspective](https://mlsanity.com/paper/2310.18162/) (2023)
- [Proportionally Representative Clustering](https://mlsanity.com/paper/2304.13917/) (2023)
- [Proportional Fairness in Non-Centroid Clustering](https://mlsanity.com/paper/2410.23273/) (2024)
- [Group Fairness in Peer Review](https://mlsanity.com/paper/2410.03474/) (2024)
- [Workload Equity in Vehicle Routing Problems: A Survey and Analysis](https://mlsanity.com/paper/1605.08565/) (2016)
- [Core-Stable Committees under Restricted Domains](https://mlsanity.com/paper/2108.01987/) (2021)
- [The Core of Approval-Based Committee Elections with Few Seats](https://mlsanity.com/paper/2501.18304/) (2025)
- [Unifying Proportional Fairness in Centroid and Non-Centroid Clustering](https://mlsanity.com/paper/2601.00447/) (2026)
- [Towards Fair and Efficient Public Transportation: A Bus Stop Model](https://mlsanity.com/paper/2411.08784/) (2024)

## Built on by (most cited first, 1 of 1)

- [Optimally Selecting Representative Agents from a Metric Space](https://mlsanity.com/paper/2608.29097/) (2026)

## Abstract (arXiv)

We study the transit stop placement (TrSP) problem in general metric spaces, where agents travel between source-destination pairs and may either walk directly or utilize a shuttle service via selected transit stops. We investigate fairness in TrSP through the lens of justified representation (JR) and the core, and uncover a structural correspondence with fair clustering. Specifically, we show that a constant-factor approximation to proportional fairness in clustering can be used to guarantee a constant-factor biparameterized approximation to core. We establish a lower bound of 1.366 on the approximability of JR, and moreover show that no clustering algorithm can approximate JR within a factor better than 3. Going beyond clustering, we propose the Expanding Cost Algorithm, which achieves a tight 2.414-approximation for JR, but does not give any bounded core guarantee. In light of this, we introduce a parameterized algorithm that interpolates between these approaches, and enables a tunable trade-off between JR and core. Finally, we complement our results with an experimental analysis using small-market public carpooling data.