Terrain Constructability and Cost Analysis
What This Tool Does
Terrain Constructability and Cost Analysis converts terrain, conflict, wetness, and access context into constructability and relative cost surfaces. It produces a constructability raster, a cost-class raster, a summary JSON, and an HTML report.
Typical Questions This Tool Helps Answer
- What is the relative construction cost surface for this project area, and which zones drive the highest grading and site preparation costs?
- Which portions of the proposed development footprint can be built at acceptable cost with minimal earthwork and site preparation?
- How does constructability and relative cost compare across the candidate site alternatives under review?
When To Use
- Preliminary constructability screening
- Relative cost comparison between development alternatives
- Early budget framing before detailed engineering estimates
What You Need
| Input | Description |
|---|---|
| DEM raster | The reference elevation raster. |
| Optional normalized rasters | Existing conflict, wetness, or access-cost layers in the range 0 to 1. |
Key Settings
| Setting | Default | Guidance |
|---|---|---|
output_prefix | terrain_constructability | Output file prefix. |
| Optional rasters | null | Leave them empty if a context layer is not available. |
What You Get
| Deliverable | Format | Description |
|---|---|---|
constructability_score | Raster | Relative constructability score. |
cost_class | Raster | Five-class relative cost map. |
summary | JSON | Run summary and QA status. |
html_report | HTML | Human-readable report. |
The summary status becomes review when the high-cost fraction exceeds 0.45.
Runtime Output Keys
result.outputs["constructability_score"]
result.outputs["cost_class"]
result.outputs["summary"]
result.outputs["html_report"]
Common Questions
Q: Which output metric should I review first?
A: Start with summary.high_cost_fraction and summary.mean_cost_class, then map class 4 and 5 concentrations in cost_class.
Q: What is a common interpretation mistake? A: Treating class values as absolute currency. Classes are relative constructability cost bands, not direct budget amounts.
Q: Which settings most change outcomes?
A: Including or excluding optional inputs (existing_conflict, wetness, access_cost) usually causes the largest shifts in high-cost area.
Q: How should project teams use these outputs? A: Use high-cost zones to adjust alignment and staging alternatives before final budget and sequencing decisions.
Results Delivery Checklist
-
summary["status"]was reviewed -
cost_classwas inspected in GIS software - High-cost areas were checked before development planning decisions
Operational Notes
cost_classis a relative constructability indicator, not a direct currency estimate.- Including
existing_conflict,wetness, andaccess_costtogether usually increases high-cost (4and5) footprint extent. - Review
high_cost_fractionwith mapped class distribution before budget and sequencing decisions.
Related Tools
terrain_constraint_and_conflict_analysiscorridor_mapping_intelligenceutility_corridor_encroachment_intelligence
References
- Runtime implementation:
wbtools_pro/src/tools/siting/terrain_constraint_and_cost.rs - Terrain and Infrastructure Siting bundle overview:
manual/pro-tools-customer/src/terrain_siting/overview.md
When To Use This Workflow
Use Terrain Constructability and Cost Analysis when you need comparative constructability/cost surfaces to rank route or site alternatives before detailed engineering estimates.