# A Force-Directed Approach for Offline GPS Trajectory Map Matching

## TL;DR

This paper introduces a novel offline GPS trajectory map matching algorithm inspired by force-directed graph drawing, which effectively handles noise and complex urban road topologies.

## Contribution

The paper proposes a new force-directed algorithm for offline map matching that improves accuracy and robustness over traditional routing-based methods.

## Key findings

- Outperforms traditional algorithms in urban dense areas
- Effectively handles noisy GPS data
- Maintains topological constraints like one-way roads

## Abstract

We present a novel algorithm to match GPS trajectories onto maps offline (in batch mode) using techniques borrowed from the field of force-directed graph drawing. We consider a simulated physical system where each GPS trajectory is attracted or repelled by the underlying road network via electrical-like forces. We let the system evolve under the action of these physical forces such that individual trajectories are attracted towards candidate roads to obtain a map matching path. Our approach has several advantages compared to traditional, routing-based, algorithms for map matching, including the ability to account for noise and to avoid large detours due to outliers in the data whilst taking into account the underlying topological restrictions (such as one-way roads). Our empirical evaluation using real GPS traces shows that our method produces better map matching results compared to alternative offline map matching algorithms on average, especially for routes in dense, urban areas.