valhalla/valhalla
Valhalla
Valhalla is an open-source routing engine that calculates optimal paths and travel times using OpenStreetMap data. It is built around a tiled routing graph framework, allowing map data to be organized into small geographic tiles for efficient regional updates and offline routing capability.
The project distinguishes itself through a multimodal routing server that combines automobile, pedestrian, bicycle, and public transit modes into single journeys. It includes a GPS trace matching engine to align noisy coordinates to the most probable road network paths and an isochrone and matrix generator for calculating travel-time polygons and distance matrices.
The engine covers a broad range of navigation capabilities, including turn-by-turn guidance, route sequence optimization for multi-stop trips, and elevation-aware routing that incorporates digital elevation models. It also supports dynamic costing models for vehicle-specific restrictions, historical and real-time traffic integration, and the generation of vector tiles for visualization.
Valhalla provides a command-line interface for standalone route execution and routing tile management.
Features
- Multimodal Planning - Combines automobile, pedestrian, bicycle, and public transportation modes into a single, optimized journey.
- Routing Engines - Provides a self-hosted navigation system using OpenStreetMap data with custom costing models and elevation profiles.
- Routing Graph Generation - Transforms open map data into a tiled graph structure for efficient routing and spatial queries.
- Tiled Routing Graphs - Organizes the road network into small geographic tiles for efficient regional updates and offline routing.
- Geographic Routing Engines - Provides a complete engine for processing geographic data and calculating routing paths.
- Road Network Routing - Valhalla snaps raw GPS coordinates to a known road network to generate accurate paths.
- Route Calculations - Valhalla computes optimal routes between sets of coordinates based on a provided routing graph and configuration.
- OSM Data Parsing - Parses OpenStreetMap extracts to generate a tiled routing graph and hierarchy for search engines.
- Routing Integration - Incorporates terrain data into routing calculations to account for slope and altitude for non-motorized travel.
- Transit Routing Engines - Uses GTFS data to provide multimodal routing options combining public transit with other modes.
- GTFS Feed Processing - Processes GTFS feeds to incorporate public transport schedules into the routing graph.
- Turn-by-Turn Navigation Guidance - Generates detailed textual and verbal maneuvers with road metadata for guiding users along a calculated route.
- Tile-Based Spatial Queries - Retrieves graph tile identifiers and coordinates based on bounding boxes or specific points.
- Elevation Data Services - Integrates terrain elevation information into route tiles using SRTM data for altitude-aware pathfinding.
- Multimodal Graph Integration - Combines road networks with GTFS transit feeds to calculate journeys involving multiple transport modes.
- Reverse Geocoding Utilities - Valhalla retrieves detailed information about roads and junctions closest to specific input points based on travel mode.
- Spatial Tile Identification - Determines which road network tiles intersect a bounding box to load data for a region.
- Tiled Routing Graph Organization - Organizes routing graphs into a tiled structure to enable partial regional updates and efficient downloading.
- Pathfinding - Implements A* algorithms to compute optimal paths by calculating edge costs and heuristics.
- Isoline Map Generators - Produces maps visualizing locations reachable from a point within a specific time or distance limit.
- Distance Matrix Calculations - Computes travel times and distances between multiple origin and destination pairs for logistics optimization.
- Isochrone Polygons - A tool for calculating travel-time polygons and distance matrices between multiple geographic origin and destination points.
- Edge Weight Calculations - Valhalla computes the cost of traversing graph edges to determine the optimal path between locations.
- Geospatial Reachability Analysis - Identifies all areas reachable from a starting point within a specific time or distance threshold.
- Job Sequence Optimizations - Determines the most efficient sequence to visit a set of locations to minimize total distance.
- Map Matching Algorithms - Valhalla correlates input coordinates to the nearest traversable edges in a routing graph.
- Map Matching Engines - Snaps noisy GPS coordinates to the most probable road network paths based on transport mode.
- Map Matching Services - Aligns noisy GPS coordinates and traces to a road network to determine the most likely path traveled.
- Multi-Stop Route Optimizations - Computes the most efficient path and sequence to visit a set of multiple locations.
- Multimodal Route Planning - Valhalla combines multiple transport modes into a single journey with support for scheduled departure and arrival times.
- Shortest Path Algorithms - Implements A* algorithms to calculate the most efficient path between nodes in the routing graph.
- Trajectory Matching - Valhalla aligns a sequence of coordinates to a road network to produce a precise trajectory.
- Shortest Path Algorithms - Calculates the minimum distance or fastest time between nodes using A* search.
- Travel Time Estimation - Creates tables of travel times and distances between multiple origins and destinations based on road network topologies.
- Traveling Salesman Problem Solvers - Solves the traveling salesman problem to determine the most efficient order of visits for waypoints.
- Turn Restriction Logic - Enforces movement constraints at intersections by labeling directed edges to ensure legal turns.
- Dynamic Routing Costing - Adjusts path weighting at runtime using plug-ins for specialized needs such as truck routing.
- Routing Tile Management - Builds routing tiles from source data and manages the download of elevation tiles for specific regions.
- Terrain and Elevation - Returns digital elevation model height for coordinates or polylines to analyze steepness.
- Route Elevation Analysis - Computes height above sea level for specific coordinates or cumulative distance and height.
- Transit Stop Lookups - Checks for the presence of public transportation stops within a specified radius of locations.
- Protocol Buffers - Uses Protocol Buffers for efficient binary serialization of routing requests and responses.
- Graph Traversal - Valhalla returns a geojson representation of a graph traversal starting from a given location.
- Probabilistic Path Selection - Valhalla returns a ranked list of the most likely routes for a given trace while filtering redundancies.
- Spatial Binning - Valhalla finds candidate edges near a given coordinate by searching spatial bins.
- Vector Tile Serving - Valhalla delivers graph representations of edges and nodes as vector tiles including detailed attributes for visualization.
- Change Tracking - Tracks versioning across a global tileset using unique identifiers to determine if data has updated.
- Offline Map Routing - Enables route calculation without an internet connection by downloading tiled graph data to the device.
- Pre-built Routing Tile Deployment - Loads existing routing tile packages to instantiate a routing engine without rebuilding from raw data.
- Tile Checksum Validation - Computes a unique checksum for every tile to identify specific areas that require updating.
- Tileset Version Validation - Assigns a build identifier to a tileset to ensure all tiles belong to the same version.
- Meeting Point Optimization - Valhalla identifies the location that minimizes total travel cost for routes originating from multiple points.
- Vector Tile Serving - Valhalla returns binary map tile data for a specific set of coordinates for visual rendering.
- Coordinate Interpolations - Valhalla filters out nearby GPS measurements and interpolates them into the route to reduce noise.
- Data Compression and Decompression - Converts historical speed profiles between compressed and decompressed states to maintain efficient data storage.
- Historical Traffic Profiling - Incorporates time-dependent speed profiles from CSV files for traffic-aware routing.
- Real-Time Traffic Integration - Adjusts route speeds using live traffic overlays to reflect current road conditions.
- Road Incident Integration - Incorporates temporary road events like construction into routing calculations.
- Bicycle Grade Optimization - Adjusts routing paths and travel times based on road grade to minimize or maximize steepness for bicycles.
- Spatial Proximity Queries - Valhalla retrieves all road segments within a specified radius of a position using a spatial grid query.
- Route Area Avoidance - Excludes specific locations or polygonal regions from path computation to steer the route away from certain areas.
- Spatial Snapping Utilities - Matches GPS coordinates to the nearest road segment using indexed spatial bins.
- Timezone-Aware Routing - Integrates global timezone data into the routing graph to support arrival and departure constraints.
- Traffic Data Integration - Integrates live traffic and historical trends into the routing graph to improve time estimates.
- Routing Configurations - Provides JSON configuration files to define how the routing engine accesses tile data and handles logging.
- Routing Engine Parameter Tuning - Adjusts engine settings like maximum route distance via JSON configuration to modify routing behavior.
- Routing Profile Configurations - Generates and validates declarative specifications for vehicle speeds and accessibility constraints.
- Plugin-Based Architectures - Utilizes a plugin-based architecture to adjust route weights at runtime based on vehicle restrictions.
- C Geospatial Libraries - Open source routing engine for OpenStreetMap data.
- Low Level Geospatial Libraries - Provides open-source routing engines.
