Lanelet2 Maps

This repo contains tools for creating and modifying maps.

Editing Lanelet2 maps

Lanelet2 maps are best edited using the OpenStreetMap-Editor JOSM. The josm folder of this package contains styles and presets for simple set-up.

This repository contains two stylesheets. One for visualizing the physical layer of the map (the markings and borders) and one for visualizing the lanelet/area layer.

To use them in JOSM: - Unzip the images in style_images.zip (containing images for traffic signs) - Under Preferences->Map Settings -> Map Paint styles -> add (+) select lanelets.mapcss and lines.mapcss to add the lanelet2 styles to JOSM. - Under Preferences->Map Settings -> Tagging Presets -> add (+) select laneletpresets.xml to add the lanelet2 tagging style to JOSM

After that, you can access the presets via Presets->lanelet2. For faster access, add them to the toolbar in Preferences->Toolbar customization.

Reading and Writing to OSM

Lanelet2 utilizes the osm xml format as default format to read and write map data. To do this, a simple mapping is done by the library to "transform" lanelet primitives into osm primitives. The Id will be the Id of the primitive (we recommend to use positive Ids, because some OSM editors treat negative Ids as something modifiable and will continue to change them), attributes will be translated to tags of the OSM primitive.

Points

Points are directly transformed to OSM Nodes. The "ele" tag is used to represent the z-coordinate of the point. It denotes the distance to the earth ellipsoid in WGS84.

LineStrings

LineStrings are transformed to OSM Ways.

Polygons

Polygons are OSM Ways as well but are identified by a tag area=yes. Start point = end point is not sufficient and also not necessary.

Lanelets

Lanelets are represented as OSM relations with a tag type=lanelet. - The right bound is a relation member of type way with role right - The left bound is a relation member of type way with role left - The centerline (if present) is a relation member of type way with role centerline - All regulatory elements are relation members of type relation with the role regulatory_element

If there are more members to the lanelet relation than the mentioned ones, Lanelet2 will raise an error.

Areas

Areas are represented as OSM relations by making use of the multipolygon representation. They have a tag type=multipolygon. The outer bound is an ordered list of relations with the role outer, the inner bounds are an ordered list of relations with the role inner. Lanelet2 parses the inner bounds in this order and starts a new hole whenever the last point of one linestring matches the first one.

Regulatory Elements

Regulatory elements are also represented as OSM relations with type=regulatory_element the parameters of a role are directly translated to relations.

All other relations (with no type or a wrong type) will be ignored when parsing .osm data.