# Combining the Connection Scan Algorithm with Contraction Hierarchies

## TL;DR

This paper presents a novel combination of Contraction Hierarchies with the Connection Scan Algorithm, significantly improving shortest-path query performance in routing applications over traditional methods like Dijkstra or A*.

## Contribution

It introduces a new method that integrates Contraction Hierarchies with the Connection Scan Algorithm, enhancing routing efficiency in weighted graphs.

## Key findings

- Improved query performance over Dijkstra and A*
- Effective integration of Contraction Hierarchies with Connection Scan
- Potential for better real-world routing applications

## Abstract

Since the first solutions finding minimally weighted routes in weighted digraphs, a plethora of literature has appeared improving the performance of shortest-path queries for use in real-world applications. In this paper, we detail how an advanced pre-processing technique for routing algorithms (which create objects known as Contraction Hierarchies) may be combined with the connection scan algorithm, an algorithm originally designed to work with public transportation networks using time tables. This provides an improvement over bi-directional Dijkstra or A${}^*$ search on Contraction Hierarchies.