WME Straighten Up!
WME Straighten Up! is a Waze Map Editor script that provides two powerful tools for cleaning up street geometry: Straighten and Simplify. Both tools help you refine road layouts by working with segment geometry nodes, but they use very different approaches for different scenarios.
Overview
| Feature |
Straighten |
Simplify |
| Purpose |
Force segments onto a perfect straight line between endpoints |
Remove redundant geometry nodes while preserving natural curves |
| Geometry Changes |
Removes all intermediate nodes; creates perfectly straight path |
Removes only unnecessary nodes; maintains original shape |
| Junction Nodes |
Moves junction nodes to align them with the straightened path |
Leaves junction nodes untouched |
| Use Case |
Correct badly warped segments; align parallel roads |
Clean up mapping artifacts; reduce excessive detail nodes |
| Aggressiveness |
Very aggressive; significantly alters geometry |
Conservative; preserves path character |
Straighten Function
What It Does
The Straighten function forces one or more connected segments to align along a perfectly straight line between their two endpoints. It:
- Removes all intermediate geometry nodes from selected segments
- Moves junction nodes to align them with the straight line path
- Ensures all segments lie on a single geometric line
When to Use Straighten
- You have segments that should be straight but have accumulated geometry errors or warping over time
- Road geometry has mapping artifacts that make a naturally straight road look curved
- You're aligning multiple segments that should form a single, perfectly straight corridor
- You need to enforce strict geometric alignment (e.g., parallel roads that should have identical bearings)
Example
Before: Road has 8 geometry nodes, slightly curved
Junction A ────────⌢────────── Junction B
After: Road has 2 geometry nodes (endpoints only), perfectly straight
Junction A ─────────────────── Junction B
Validation Checks
Before straightening, the script checks for:
- >10 segments selected — Confirms mass edit intent
- Segments not connected — Warns if segments don't form a continuous path
- Different street names — Warns if segments have conflicting names
- Micro dog legs — Detects geometry nodes near junctions that affect turn instructions
- Large junction moves — Warns if moving a junction node >5m
Simplify Function
What It Does
The Simplify function intelligently removes redundant geometry nodes from segments without straightening them. It:
- Uses the Ramer-Douglas-Peucker algorithm to reduce node count based on deviation distance
- Preserves the original path shape and curvature
- Removes nodes that deviate less than your chosen tolerance from the path
- Leaves junction nodes untouched (no junction moves)
When to Use Simplify
- Road geometry has too many detail nodes from aerial imagery or over-mapping
- Segments have accumulated many redundant nodes over time
- You want to clean up geometry without changing the road's natural curves
- You're reducing data density in a complex area (many small nodes)
- Survey nodes or GPS traces created excessive intermediate nodes
Tolerance Settings
Choose how aggressively nodes are removed:
| Tolerance |
Effect |
Use Case |
| 1m (default) |
Minimal removal; preserves fine detail |
Carefully maintained areas; detailed curves |
| 3m |
Moderate removal; good balance |
General cleanup; most urban streets |
| 5m |
Aggressive removal; reduces complexity |
Suburban/rural roads; heavily mapped areas |
| 10m |
Very aggressive; major simplification |
Regional overview; extreme detail reduction |
Higher tolerance = more nodes removed.
Example
Before: 12 nodes, curved road with mapping detail
After: 4 nodes, same curve preserved, less detail
Result: Road still curves naturally, just cleaner
Validation Checks
Before simplifying, the script checks for:
- >10 segments selected — Confirms mass edit intent
- Micro dog legs — Detects geometry nodes near junctions that affect turn instructions
How to Use
Installation
- Install from GreasyFork: WME Straighten Up!
- Use a userscript manager (Tampermonkey, Greasemonkey, etc.)
- Buttons appear automatically in WME Segment Edit panel
Straighten Workflow
- In WME, select one or more connected segments to straighten
- Click the "Straighten" button in the Segment Edit panel
- Review any confirmation dialogs (safety checks)
- Confirm if prompted about micro dog legs or junction moves
- Done! Script updates geometry and shows confirmation
Simplify Workflow
First time or changing tolerance:
- Click WME Straighten Up! settings (gear icon on WME toolbar)
- Go to "Simplify Options" section
- Select tolerance: 1m, 3m, 5m, or 10m
- Close settings (your choice is saved)
Each time you simplify:
- In WME, select one or more segments to simplify
- Click the "Simplify" button in the Segment Edit panel
- If micro dog legs detected, confirm removal or cancel
- Done! Script removes redundant nodes and shows how many
Configuration & Settings
Access settings via the WME Straighten Up! settings panel (gear icon).
Straighten Settings
| Setting |
Options |
Default |
Purpose |
| Sanity Check (>10 segments) |
Error, Warning, Pass |
Warning |
Require confirmation for mass edits |
| Non-Continuous Selection |
Error, Warning, Pass |
Warning |
Warn if segments aren't connected |
| Conflicting Names |
Error, Warning, No Warning |
Warning |
Warn if segment names differ |
| Long Junction Move |
Error, Warning, Pass |
Warning |
Warn if junctions move >5m |
| Micro Dog Legs |
Error, Warning, Pass |
Warning |
Warn before removing nodes near junctions |
Simplify Settings
| Setting |
Options |
Default |
Purpose |
| Simplify Tolerance |
1m, 3m, 5m, 10m |
1m |
How aggressively to remove nodes |
| Sanity Check (>10 segments) |
Error, Warning, Pass |
Warning |
Require confirmation for mass edits |
| Micro Dog Legs |
Error, Warning, Pass |
Warning |
Warn before removing nodes near junctions |
Edge Cases & Limitations
Straighten
- Single-segment straightening — Works, but rarely needed (single segments already defined by endpoints)
- Segments with <3 nodes — Cannot be straightened (already minimal)
- Non-connected path — May produce unexpected results if segments don't form a continuous line
- Junction moves > 5m — Flagged as potential error (may indicate poor input geometry)
Simplify
- Segments with <3 nodes — Skipped (nothing to simplify)
- Very tight curves — May be over-simplified if tolerance is too high (reduce to 1m)
- Turn instructions — Simplification may affect turn routing if micro dog legs are removed
- Micro dog leg nodes — Will be detected and warned before removal
Troubleshooting
"No segments selected" error
- Make sure you've selected at least one segment before clicking the button
- Segments must be selected in the WME Segment Edit panel
"Sanity check: You selected many segments"
- You've selected >10 segments
- Confirm in the dialog if you want to proceed with the mass edit
"Non-continuous segments" warning (Straighten only)
- You've selected segments that aren't all connected to each other
- For Straighten: select only segments that form a connected path
- For Simplify: this isn't an issue (processes each segment independently)
"Conflicting names" warning (Straighten only)
- The selected segments have different street names
- This could create mapping errors
- Verify all segments should have the same name, or select fewer segments
Straighten didn't work / segments look the same
- Check that you selected multiple segments (not just one)
- Verify they were actually connected (form a continuous path)
- The segments may already be perfectly straight
Simplify removed too many nodes / not enough
- Too many removed? Use a smaller tolerance (1m instead of 10m)
- Not enough removed? Use a larger tolerance (5m or 10m instead of 1m)
- Change the tolerance setting and try again
"Micro dog legs detected" warning
- The segment has geometry nodes very close (< 2m) to junctions
- Removing them could alter turn instructions (e.g., Keep Right → Turn Right)
- These may be intentional placements to force specific routing
- Option 1: Accept the warning to remove them anyway
- Option 2: Use Turn Instruction Override (TIO) or Voice Instruction Override (VIO) instead
- Option 3: Cancel and leave them as-is
Data Safety
Both functions only modify segment geometry — they do not change:
- Street names
- Road types
- Turn restrictions
- Speed limits
- Lane guidance
- Any other segment properties
All changes are performed via the WME SDK and immediately saved to WME. Use Ctrl+Z (browser undo) to revert if needed.
Credits
- Original script concept by jonny3D, impulse200, and dBsooner
- Modern enhancements and Simplify function by JS55CT
License
GPLv3
Feedback & Issues
