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Step 6 of 7
25 min

Roads and Path Digitization

Road and path mapping creates the transportation network that connects buildings, enables navigation, and supports logistics planning. Accurate road data is essential for emergency response, delivery services, and community development.

Roads in OpenStreetMap are represented as 'ways' - sequences of connected nodes that follow the centerline of the road. Unlike buildings (which are closed shapes), roads are open lines.

Part 1: Road Classification System

OpenStreetMap uses a detailed hierarchy of road types. Proper classification is critical for routing and map rendering.

Road Type Hierarchy

  • highway=motorway - Major divided highways with controlled access
  • highway=trunk - Important non-motorway routes
  • highway=primary - Major roads connecting cities
  • highway=secondary - Roads connecting towns
  • highway=tertiary - Roads connecting smaller settlements
  • highway=residential - Streets in residential areas
  • highway=unclassified - Minor public roads
  • highway=service - Access roads to buildings, parking lots
  • highway=track - Agricultural/forestry tracks
  • highway=path - Footpaths, hiking trails
  • highway=footway - Dedicated pedestrian paths in urban areas

Classification Accuracy: Misclassifying roads affects GPS routing. A residential street tagged as 'primary' will route heavy traffic incorrectly. When uncertain, check validated neighboring tasks or ask in project chat.

Part 2: Drawing Roads in JOSM

Roads are drawn using the standard line drawing tool. The key is following the road centerline accurately.

Road Drawing Process

  • 1. Press 'A' to activate the drawing tool
  • 2. Click to place first node at road start
  • 3. Click along road centerline at intervals
  • 4. Add nodes at curves, intersections, and direction changes
  • 5. Press ESC when complete (don't double-click to finish)
  • 6. Road remains selected for tagging
  • 7. Add appropriate highway= tag from list above

Pro Tip: Place nodes closer together on curves and farther apart on straight sections. This creates smooth curves while minimizing unnecessary nodes.

Part 3: Road Intersections and Connections

Where roads meet, they must share nodes to enable routing. Disconnected roads appear fine visually but break navigation.

Creating Proper Intersections

  • Zoom in to maximum detail at intersection
  • Draw first road completely, including through intersection
  • For second road: click directly ON existing road node at intersection
  • JOSM shows highlighting when hovering over existing node
  • This creates shared node, connecting the roads
  • Both roads can now route through the intersection
  • Never have two roads cross without sharing a node

Critical: Roads that visually cross but don't share a node create 'broken' routing. Always verify connections by selecting roads and checking shared nodes.

Part 4: Road Names

Adding road names dramatically improves map usability and enables address-based routing.

Naming Roads

  • Only add names if visible on signage in imagery or confirmed by project
  • Tag: name=Street Name (with proper capitalization)
  • Use local language for name (name=Rue de la Paix)
  • Add English translation if different (name:en=Peace Street)
  • Don't abbreviate (write 'Street' not 'St', 'Avenue' not 'Ave')
  • Don't add road type prefix (name=Main Street, not name=Main)
  • Unnamed rural roads remain untagged for name

Part 5: Road Surface and Conditions

Surface tags inform routing decisions for different vehicle types.

Surface Tagging

  • surface=paved - Asphalt or concrete (smooth, all-weather)
  • surface=unpaved - Gravel, dirt (rough, weather-dependent)
  • surface=ground - Natural earth surface
  • tracktype=grade1 through grade5 - Quality rating for tracks
  • Only add surface tags if clearly visible in high-resolution imagery

Expert Tip: In many mapping projects, surface tagging is optional. Always check project instructions before spending time on surface attributes.

Key Takeaways

  • Roads are open lines following centerline, buildings are closed shapes
  • highway= tag determines road type and routing priority
  • Roads must share nodes at intersections to enable routing
  • Add names only when confirmed by imagery or project instructions
  • Press 'A' for line tool, 'ESC' to finish (not double-click)
  • Check project instructions for required/optional road attributes
  • When uncertain about classification, check validated adjacent tasks