What is Lanelet2?
Lanelet2 is an open HD map format and C++ library originally developed by the FZI Research Center for Information Technology and now widely used as the HD map representation in Autoware and many research stacks. Its central idea: roads are bundles of small “lanelets”, each bounded by a left and right linestring, with explicit topological and regulatory relations.
The original Lanelet2 paper (Poggenhans et al., 2018) is a good primer.
What a Lanelet2 map looks like
Section titled “What a Lanelet2 map looks like”Physically, a Lanelet2 map is an OpenStreetMap XML file with extra tags. That gives you:
- Nodes — single points (latitude, longitude, optional elevation).
- Ways — ordered sequences of nodes. In Lanelet2, ways act as lane boundaries, stop lines, traffic light supports, and more.
- Relations — typed groupings. A
laneletrelation pairs a left and right way and may carry attributes for speed limit, road type, one-way flag, etc.
On top of this, Lanelet2 ships with a routing graph, regulatory elements (traffic lights, right-of-way, speed limits, stop signs), and geometric utilities.
Lanelet2 vs OpenDRIVE
Section titled “Lanelet2 vs OpenDRIVE”Both describe HD maps but optimise for different sides of the AV stack:
| Aspect | Lanelet2 | OpenDRIVE |
|---|---|---|
| Geometry | Polylines (linestrings) | Analytical (arc, spiral, polynomial) |
| Topology | Explicit lanelet adjacency / sequence | Lane sections + junction connections |
| Native consumers | Autoware, planning research, ground truth | Simulators (CARLA, esmini, RoadRunner) |
| File format | OSM XML | Bespoke XML |
| Editing ergonomics | Reasonable to hand-edit small areas | Hard to hand-edit at any scale |
Lanelet2 is generally simpler to inspect by hand. OpenDRIVE is more precise for simulator consumers.
Common authoring tools
Section titled “Common authoring tools”- TIER IV Vector Map Builder — a free browser-based Lanelet2 editor designed for Autoware. Lane authoring with regulatory elements (traffic lights, stop lines, crosswalks, parking, …) and point cloud reference layer. Often the first recommendation for new Autoware users today.
- JOSM with the Autoware Lanelet2 plugin — the classic OSM desktop editor extended for Lanelet2. Mature and powerful; Autoware-compatible output sometimes needs manual fixup.
- Hand-edited OSM XML — viable for small fixes, painful at scale.
- drawtonomy — imports a Lanelet2
.osmfile for visualization and basic geometry edits.
Where drawtonomy fits
Section titled “Where drawtonomy fits”drawtonomy is not a replacement for Vector Map Builder or JOSM. Its Lanelet2 support covers a narrow slice:
- Imports a Lanelet2
.osmand renders lanelets as editable Lane / Linestring shapes. - Lets you reshape boundaries and do basic geometric tweaks, then re-export.
- Useful for inspection, teaching, figure preparation (papers, slides), and small geometric fixes.
What drawtonomy doesn’t do:
- Authoring regulatory elements in the UI. Imported regulatory elements are preserved on re-export through a sidecar mechanism, but creating or editing them visually is out of scope. Use Vector Map Builder or JOSM for that.
- City-scale or survey-grade authoring.
- Bulk operations across thousands of lanelets.
For real Lanelet2 authoring, use Vector Map Builder (for Autoware-targeted maps) or JOSM (for general OSM-style editing). drawtonomy is for the visualization + light-geometry-edit corner.
Related reading
Section titled “Related reading”- Autoware HD maps — how Lanelet2 plugs into Autoware.
- Import Lanelet2 OSM maps — how to load one into drawtonomy.
- Compare: drawtonomy vs JOSM
- Compare: drawtonomy vs Vector Map Builder
- Compare: drawtonomy vs MapToolbox