# LegalFarePlan: A Label-Setting Framework for Fare-Transparent Urban Rail Route Planning under Non-Additive Fare Rules

arXiv: https://arxiv.org/abs/2607.09755 · HTML: https://mlsanity.com/paper/2607.09755/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 4 of its 16 references that are in the map.
- First posted on arXiv 5 Jul 2026.

## Builds on (most cited first, 4 of 4)

- [Route Planning in Transportation Networks](https://mlsanity.com/paper/1504.05140/) (2015)
- [Connection Scan Algorithm](https://mlsanity.com/paper/1703.05997/) (2017)
- [Trip-Based Public Transit Routing](https://mlsanity.com/paper/1504.07149/) (2015)
- [Fast One-to-Many Multicriteria Shortest Path Search](https://mlsanity.com/paper/2201.12684/) (2022)

## Abstract (arXiv)

Urban rail fare systems may be non-additive: the fare of a single paid journey from an origin to a destination can differ from the sum of fares over multiple legally separated journey legs. This paper presents LegalFarePlan, a fare-transparent route-planning framework that models legal exit-and-reentry operations as explicit, auditable constraints. Given a transit network, fare function, transfer rules, station-level exit/re-entry costs, an extra-time budget, and a split limit, the planner computes explainable route plans over paid journey segments. The artifact implements Dijkstra shortest-time and direct route-planner baselines, a greedy split heuristic, bounded exact label-setting, and Pareto-frontier search. Evaluation uses controlled synthetic data and a 57-station semi-synthetic benchmark with 360 OD pairs. On the semi-synthetic benchmark, bounded exact search identifies positive modeled fare reductions for 71.11% of OD pairs, with mean reduction 3.78 and maximum reduction 9.0 synthetic fare units under a 45-minute extra-time budget. These results demonstrate method behavior and reproducibility; they are not empirical conclusions about MTR or any transit operator.