We are pleased to announce the latest major release of OTP: 0.9. (Technically, as of this posting the current release is 0.9.1, with the first bug-fix followup release having already been cut.) Note that 0.8 was skipped; the numbering reflects the team’s desire, as discussed in the 9/27 check-in, for this release to be the final major release prior to a long-awaited 1.0 release of OTP.
Major enhancements in 0.9 include the following:
- RAPTOR Implementation: David Turner has completed implementation of RAPTOR, a different algorithm for transit routing that yields significantly improved search times in larger graphs compared to the A* algorithm traditionally used by OTP. This paper from Microsoft Research describes the theoretical underpinnings of RAPTOR, and instructions for enabling RAPTOR in OTP can be found on the wiki.
- Graph Loading API: OTP’s multiple graph support is seeing more active use (within the context of the OTP Deployer application, among other places), heightening the need for a more robust mechanism for dynamic graph management. The new RESTful API, written by Andrew Byrd, accomplishes this, using the existing ‘/routers’ API method and standard HTTP commands such as GET, PUT, and DELETE. Included is the new ability to “evict” a graph from an OTP server, freeing up its memory footprint for other graphs.
- Real-Time Vehicle Updates: 0.9 includes initial support for trip planning based on real-time vehicle locations. This work was completed to support an initial test case in the Netherlands using the Dutch KV8 standard, but it lays much of the groundwork for more generalized real-time support, including consumption of GTFS-RT vehicle locations (OTP already supports the trip alerts component of GTFS-RT). Look for more on this in future versions.
- Smaller Graph Sizes, accomplished through more efficient handling of debugging annotations. This has reduced graph size by as much as 50 percent in initial testing.
Additional 0.9.x bug fix releases are likely in the coming weeks, but the next major release will be 1.0, hopefully before the end of the year. The 1.0 release is expected to include expanded support for real-time planning and the new mobile-optimized user interface developed for bikeplanner.org, among other additions and enhancements. Stay tuned!
