Objective: Map missing turn lanes from secondary and up in 30 US cities.

Team: @mapbox/team-data

Features to map: Turn lanes (motorway, trunk, primary and secondary) from satellite imagery

Focus Area: 30 top cities in US as per population

Available data sources

Tasks

JOSM Workflow

Setup

• Activate the following in from JOSM preferences > Map Settings
  • Map Paint Styles: Lanes and road attributes
  • Tagging Presets: lane attributes
• Filter out non road features with boundary: | leisure: | landuse: | waterway: | amenity: | natural: | building:
• Add inverse filter: highway=motorway|trunk|primary|secondary|*link|motorway_link or untagged
• Read http://wiki.openstreetmap.org/wiki/Key:turn:lanes
• Read https://github.com/mapbox/mapping/wiki/Mapping-guide-for-turn-lanes-from-imagery
• Install the 🔪 tool in JOSM to easily split the roads: https://wiki.openstreetmap.org/wiki/JOSM/Plugins/Knife-tool

Mapping

• Check the roads for turn lanes at exits and entry points
  
• Split the road into segments based on the total number of lanes for the segment
• For each road segment tag the turn lanes based on the road markings in the direction of the way. Eg. turn:lanes=left|through|right. See OSM turn:lanes
• For bi-directional segments, use turn:lanes:backward= and turn:lanes:forward= to specify turn lanes in each direction.
• Verify correct tagging using the Lane attributes style
  

Issues to keep in mind:

• For QA and edge cases in turn lanes mapping and how to handle them**(parking lanes, splitting roads for start and end of turn lanes, handling of dual carriageways, etc)** look into the QA for turn lane data document.

Changeset Comment: Add missing turn lanes from satellite imagery https://github.com/mapbox/mapping/issues/180

Source: Bing/Mapbox/USGS Large Scale Imagery

Turn lane mapping tickets: #144, #153