Valhalla Traffic Integration for Careem

Overview

A Python-based solution for integrating historical traffic data with Valhalla's routing engine to improve ETA accuracy for Careem's ride-hailing platform in Amman, Jordan. This implementation enhances Valhalla's routing capabilities without modifying its core C++ codebase.

Prerequisites

• Python 3.x
• Osmium Tool
• Valhalla routing engine
• OSRM (for validation)

Setup and Configuration

Installing Valhalla

Follow the gis-ops guide for installing Valhalla on Ubuntu.

Running Valhalla

For basic Valhalla configuration and running instructions, see the gis-ops guide for running Valhalla.

Project-Specific Setup

After installing and configuring Valhalla:

1. Clone the repository:

   git clone https://github.com/muhammadazzazy/osm-valhalla-traffic-mapper.git
   cd osm-valhalla-traffic-mapper

2. Download Jordan OSM data:

   ./scripts/download_jordan_osm.sh

3. Extract Amman region:

   ./scripts/extract_amman_data.sh

Project Structure

osm-valhalla-traffic-mapper/
├── src/
│   ├── routes.py                 # OSRM vs Valhalla distance comparison logic
│   ├── graph_id.py               # Python implementation of the to_string functionality provided by Valhalla
│   ├── predicted_speeds.py       # Historical speeds conversion to DCT-II functionality
│   ├── main.py                   # Traffic CSV file preparation and writing utilities 
│   ├── get_etas.py               # Valhalla ETA extraction functionality
│   ├── speeds_checker.py         # Speed-limit violation validator
│   ├── speeds_extractor.py       # Speed data extraction from JSON
│   └── valhalla_way_id_mapper.py # OSM way ID mapping tools
│   └── valhalla_monitor.py       # Traffic CSV monitoring for automating updates to routing graph
├── scripts/
│   ├── download_jordan_osm.sh    # Script to download Jordan OSM data
│   └── extract_amman_data.sh     # Script to extract Amman region data using Osmium

Source Files (src/)

Route Processing

• routes.py: Validates routing accuracy by comparing Valhalla and OSRM distance calculations
• get_etas.py: Extracts and processes ETAs from Valhalla
• graph_id.py: Handles Valhalla graph ID conversion and processing

Speed Data Management

• predicted_speeds.py: Converts historical speed data using DCT-II functionality
• speeds_checker.py: Validates speed data against Jordan's traffic regulations
• speeds_extractor.py: Extracts speed data from JSON format

Data Integration

• main.py: Prepares and writes traffic CSV files
• valhalla_way_id_mapper.py: Maps OSM way IDs to coordinates

Scripts (scripts/)

• download_jordan_osm.sh: Downloads latest Jordan OSM data
• extract_amman_data.sh: Extracts Amman-specific region using Osmium

Core Components

Routing System Integration

The system integrates with Valhalla through:

• Graph ID conversion matching Valhalla's internal format
• OSM way ID mapping for coordinate pairs
• Batch processing support for routing requests

Traffic Data Processing

Processes historical traffic data to enhance ETA accuracy:

• Processes 2016 weekly speed patterns (5-minute intervals)
• Extracts day/night speed variations
• Validates against local speed limits
• Prepares data in Valhalla-compatible format

Contributing

Contributions welcome via pull requests.

Acknowledgments

• OpenStreetMap contributors
• Valhalla and OSRM teams