Validation Guide

Validation Guide⚓︎

This section covers how to validate mapped pedestrian infrastructure tasks in the OSM US Tasking Manager for an OpenSidewalks project.

Quick Links⚓︎

• Mapping Guide: Mapping Guide (review this before validating!)

• Join the Team: OpenSidewalks Validators Team (requires approval by TCAT staff)

  

What is Validation?⚓︎

Validation is the process of reviewing the edits of other contributors and evaluating the mapped features to ensure they are:

1. Correctly shaped - Lines and points placed accurately
2. Properly aligned - Features match real-world locations in imagery
3. Connected - Pedestrian features are connected to form a network
4. Tagged correctly - Features use the required tags

Validators should have some mapping experience and be familiar with the Mapping Guide before validating others' work.

Getting Started⚓︎

1. Find Tasks Ready for Validation⚓︎

1. Go to the project page for the project you'd like to contribute to
2. Select Contribute at the bottom right
3. Look for tasks ready for validation (blue tiles)
4. Select an already-mapped, blue task and click Validate selected task

2. Review Task History⚓︎

Before validating, check the History tab to see:

• Who mapped the task
• Any comments from the mapper
• Previous validation attempts

Validation Checklist⚓︎

1. Crossings⚓︎

• Crossings are drawn as ways across streets
• Each crossing has curb nodes at both ends
• A middle node connects the crossing to the road
• Crossing ways are tagged, at minimum: highway=footway + footway=crossing
• Crossing nodes are tagged, at minimum: highway=crossing
• crossing:markings=yes or crossing:markings=no (or a more detailed value) is set correctly based on imagery

Common Issues:

2. Curbs⚓︎

• Curbs are nodes at the edges of the street
• Curb type matches imagery: kerb=lowered, raised, or flush
• Curbs are tagged, at minimum: barrier=kerb

Common Issues:

3. Sidewalks⚓︎

• Sidewalks are drawn as ways along the center of the path
• Sidewalks are tagged, at minimum: highway=footway + footway=sidewalk
• Sidewalks connect to service roads (driveways) where they intersect via a node

Common Issues:

4. Connectors⚓︎

• Short lines connect curbs to sidewalk centerlines
• Connectors are tagged: highway=footway + footway=sidewalk + (optionally) crossing_link=yes
• One end connects to a curb node, the other to the sidewalk centerline

How to Fix Issues⚓︎

Move Features⚓︎

1. Select the feature (node or way)
2. Drag it to the correct location
3. If you accidentally move something else or only dragged to check connectivity, select the Undo button (keyboard shortcut: Ctrl+Z)

Add Missing Tags⚓︎

1. Select the feature
2. In the left panel, search for the correct preset (e.g., "Lowered Curb")
3. Alternatively, manually add tags in the expandable "Tags" table section

Connect Features⚓︎

If the editor shows a warning about disconnected features:

1. Select the feature
2. Click the warning message
3. Choose Connect the features to snap them together
4. Add tags (e.g., highway=crossing) as necessary

Tips for Validators⚓︎

• Use street-level imagery: Enable Bing Streetside or Mapillary to verify curb types
• Check connectivity: Make sure features are connected and there are no gaps in the pedestrian network that don't exist on the ground
• Be constructive: Leave helpful comments when requesting changes
• Focus on pedestrian features: While you are free to fix other errors you find, prioritize crossings, curbs, and sidewalks

Completing Validation⚓︎

If Everything Looks Good⚓︎

1. Save and upload any minor corrections you made
2. In the Tasking Manager panel on the right, answer Yes to "Is this task well mapped?"
3. Click Submit task

The task will turn from blue to green on the map to confirm that it has been validated.

If Issues Remain⚓︎

1. Save and upload any corrections you made
2. In the Tasking Manager panel on the right, answer No to "Is this task well mapped?"
3. Add a Comment describing what needs fixing
4. Click Submit task

The task will return to the mapper for further work.