
Traffic Capacity & Demand Model Builder
Build defensible traffic capacity and demand models for transportation planning
What You Can Do
You can create evidence-based traffic models that synthesize field data, historical counts, and planning assumptions into defensible projections for 5, 10, and 20-year planning horizons. The skill guides you through volume forecasting, intersection capacity analysis, scenario modeling, and sensitivity testing—producing peer-review-ready documentation that meets NEPA, traffic impact study, and agency requirements.
Features
Develop baseline demand forecasts from AADT counts, turning movements, and historical trend analysis
Analyze intersection and corridor throughput under current and future conditions using structured methodologies
Build baseline, optimistic, and pessimistic growth scenarios with documented assumptions for corridor and area-wide studies
Generate defensible growth assumptions by synthesizing historical data, development pipelines, and demographic trends
Test model robustness by varying key assumptions (growth rates, modal splits, land-use changes) and documenting impacts
Produce traffic impact study narratives, model assumptions tables, and limitation statements meeting regulatory and peer-review requirements
Consolidate traffic counts, permits, buildout projections, and external data into coherent demand forecasts
Validate consultant-developed models against technical standards and identify documentation gaps
Example Output
Example 1: 10-Year Volume Projection
Input: Current AADT of 18,500 vehicles/day on arterial corridor, 5-year historical growth at 2.1% annually, planned 350-unit residential development within study area
Output:
- Year 5 projected volume: 20,450 vehicles/day (2.1% annual growth)
- Year 10 projected volume: 22,650 vehicles/day with development-induced demand: +840 vehicles/day
- Growth rate sensitivity: ±0.5% annual variation = ±1,200 vehicles/day range
- Documentation: Growth assumption narrative, source data summary, limitation statement regarding development timing uncertainty
Example 2: Intersection Capacity Analysis
Input: Signalized intersection peak-hour volumes (NB left: 180, NB through: 520, NB right: 140), existing signal timing, v/c ratio currently 0.82
Output:
- Current LOS: C (v/c = 0.82)
- Year 10 projected LOS: D (v/c = 0.94) with cumulative area growth
- Capacity constraint identified: northbound through movement
- Mitigation alternatives: signal retiming (+0.08 v/c improvement) or exclusive left-turn phase (+0.12 v/c improvement)
- Documented analysis table with assumptions, methodology reference, and peer-review compliance checklist
Example 3: Growth Scenario Comparison
Input: Base case, optimistic buildout (+25% residential), pessimistic buildout (-15% commercial)
Output: Three-scenario table showing Year 20 AADT projections, peak-hour volumes, LOS outcomes at critical intersections, and cost implications for each scenario with documented rationale for assumptions
What's Included
- SKILL.md: Complete instruction file with structured prompts for volume projections, capacity analysis, and scenario modeling
- Volume Projection Template: Spreadsheet-ready framework for AADT forecasting with growth rate sensitivity analysis
- Capacity Assessment Checklist: Peer-review validation tool for intersection and corridor throughput analysis
- Scenario Modeling Worksheet: Baseline, optimistic, and pessimistic growth scenario builder with assumption documentation
- Traffic Impact Study Documentation Template: Narrative and table formats for regulatory submission and public agency standards
- Model Assumption Validation Guide: Framework for testing growth rates against historical trends and development pipeline data
Who It's For
- Traffic/Transportation Engineers — Building defensible models for planning projects, impact studies, and corridor analyses
- Transportation Planners — Developing demand forecasts and scenario analyses for master plans and long-range planning
- Public Agency Staff — Peer-reviewing consultant traffic models and validating assumptions for regulatory compliance
- Civil Engineering Consultants — Supporting traffic impact study preparation with structured, AI-assisted modeling workflows
- Infrastructure Project Managers — Generating supporting documentation for environmental reviews and feasibility studies
Best For
- 5-, 10-, and 20-Year Traffic Projections — Baseline demand forecasting with documented growth assumptions
- Intersection and Corridor Capacity Analysis — Level of service (LOS) calculations and throughput assessments under current and future conditions
- Scenario Modeling for Development — Buildout scenarios, land-use sensitivity analysis, and infrastructure impact assessment
- Traffic Impact Study Documentation — Peer-review-ready narratives, assumption tables, and technical appendices meeting regulatory standards
- Growth Rate Validation — Synthesizing historical count data, demographic trends, and development pipeline to support defensible assumptions
- Sensitivity and Risk Analysis — Testing model robustness across varying growth rates, modal splits, and land-use assumptions





