Scalable Isocontour Visualization in Road Networks via Minimum-Link Paths

TL;DR

This paper presents efficient heuristics and a linear-time algorithm for computing minimal-link isocontours in large-scale road networks, enabling fast and accurate visualization of reachable areas within resource limits.

Contribution

It introduces practical heuristics and a new linear-time algorithm for minimum-link paths, improving the efficiency of isocontour visualization in large road networks.

Findings

Algorithms answer queries in a few milliseconds on average.

Heuristics produce accurate isocontours with minimal segments.

Experimental results demonstrate excellent practical performance.

Abstract

Isocontours in road networks represent the area that is reachable from a source within a given resource limit. We study the problem of computing accurate isocontours in realistic, large-scale networks. We propose polygons with minimum number of segments that separate reachable and unreachable components of the network. Since the resulting problem is not known to be solvable in polynomial time, we introduce several heuristics that are simple enough to be implemented in practice. A key ingredient is a new practical linear-time algorithm for minimum-link paths in simple polygons. Experiments in a challenging realistic setting show excellent performance of our algorithms in practice, answering queries in a few milliseconds on average even for long ranges.