Solari

Solari is a high-performance transit routing engine built using the RAPTOR algorithm, optimized for lightweight, global-scale public transit routing. Designed to serve developers building applications requiring fast and resource-efficient transit planning (e.g., maps apps, trip-planning APIs), it avoids heavy preprocessing steps while supporting planet-scale coverage through memory-mapped timetables.

Key Features

• Lightweight & Fast:

  • Outperforms MOTIS/Transitous by anecdotally observed 5-10x in query speed.
  • Single-core routing across the continental U.S. completes in seconds; local routes usually resolve in <250ms.

• Planet-Scale Coverage:

  • Memory-mapped timetable data allows a single instance to handle global networks with minimal RAM usage (via memmap2).

• Multi-Agency Support:

  • Load multiple GTFS feeds from a directory for seamless cross-agency routing.

• Timezone Awareness:

  • Automatically handles timezone conversions based on GTFS feed data. Developers are responsible for converting epoch timestamps to local time in their app layer.

• HTTP API Endpoint:

  POST /v1/plan

  Example request:

  curl -d '{"from":{"lat":47.679591,"lon":-122.356388},"to":{"lat":47.616440,"lon":-122.320440},"start_at":1742845000000}' \
       https://transit.maps.earth/v1/plan

• GTFS Compatibility:

  • Supports modern GTFS feeds via the gtfs-structures crate.
  • No real-time (GTFS-RT) support yet; prioritized roadmap features include alerts, delays and vehicle position updates.

Getting Started

Prerequisites

1. Rust (rustc >= 1.85 tested).
2. OpenSSL development package: Install via your OS's package manager (e.g., libssl-dev on Ubuntu).

Quickstart Commands

Step 1: Build the Timetable Database

# For a single GTFS feed:
cargo run --release --bin build_timetable -- \
    --base-path /path/to/timetable \
    --gtfs-path gtfs.zip

# For multi-agency feeds (directory of .zip files):
cargo run --release --bin build_timetable -- \
    --base-path /path/to/timetable \
    --gtfs-path ./gtfs_feeds/

Step 2: Run the API Server

cargo run --release --bin serve -- --base-path /path/to/timetable

Architecture

• RAPTOR Algorithm: Implements all pruning rules from the original paper for optimal performance.
• Memory Mapping: Uses memmap2 to load timetable data directly from disk, enabling fast access without RAM overhead.
• Designed for Modularity: Decouples routing logic from geocoding/external services (e.g., uses Valhalla for transfer routes, but otherwise allows easy integration into an existing stack).

Performance Benchmarks

Metric	Solari	OpenTripPlanner/MOTIS
Query Latency	150ms - 2.5s	~150ms-1 minute
Memory Usage	~1.5GB (global)	Higher? (OTP: ~4GB+, MOTIS=?)

Note: Benchmarks are informal and based on limited testing. Systematic comparisons pending.

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Roadmap

• GTFS-RT Support (priority order):
  1. Service alerts and closures
  2. Real-time delays
  3. Vehicle positions
• Performance Quantification: Come up with better benchmarks against MOTIS and OpenTripPlanner.
• rRAPTOR Implementation: Long-term goal for multi-departure-time routing.
• Documentation: Ongoing work to finalize API response formats and provide detailed guides.

Contributing

• Solari is in active development; contributions (documentation, testing, or features) are welcome.
• Check the repository's issue tracker for tasks, but note there are no formal contribution guidelines yet.

Known Limitations

• No Real-Time Updates: Only static GTFS feeds supported currently.
• API Stability: The /v1/plan response format may evolve as documentation finalizes, but no compatibility breaking changes to the v1 endpoint after the initial release.

When to Use Solari?

You may want to use this project if you need:

• Fast, lightweight routing for global-scale transit networks on modest hardware.
• A minimal API layer that integrates easily with modern web stacks (geocoding, map rendering handled externally).

Avoid if you require:

• Full-featured trip-planning like OpenTripPlanner's extensive customization or real-time capabilities.

License

Apache-2.0