4 YEARS EXPERIENCE
Stu Zhang
Transport Modeller / Assets Analyst
§ Service 004 · Transport Modelling
Transport Modelling
Microsimulation, mesoscopic and macroscopic transport modelling for business case support, corridor option testing and intersection performance assessment. Bus-hub patronage, crash and dashboard models. NZMUGS-member modelling team.
Who it's for
- NZTA Waka Kotahi
- Local councils
- Developers
- Infrastructure & alliance partners
The problem we solve
Modelling earns its place when it answers the actual question — does this intersection work, does this corridor option stack up, what does the business case need — at the right level of detail. Too coarse and it misses the problem; too heavy and it costs more than the decision is worth and buries the answer in its own complexity.
We scope the model to the decision: SIDRA for intersection and network performance, Aimsun for microsimulation where interactions matter, and strategic or dashboard analysis where that's the right grain. The output is a result a business case or a council reviewer can rely on.
What's included
- AIMSUN
- SIDRA Networks
- Power BI dashboards
- Custom Python / R analysis
What you get
- Intersection and network performance modelling (SIDRA)
- Microsimulation of corridor and network options (Aimsun)
- Option testing and sensitivity analysis for business cases
- Patronage, crash and bespoke analytical models
- Power BI dashboards and custom Python / R analysis
- Model build documentation with calibration and validation record
How we work
- 01
Scope to the decision
We match the approach — SIDRA, Aimsun, strategic or dashboard — to the decision being made, so the model is fit for purpose and neither over- nor under-built.
- 02
Build & calibrate
We build the model on observed data and calibrate and validate it against counts and travel times, so the base reflects reality.
- 03
Test options
We run the option set and sensitivity tests, isolating what actually drives the result.
- 04
Report for decisions
We report findings in terms a business case, a council or an RCA reviewer can use — with the assumptions and limits stated up front.
Standards
- NZTA Transport Model Development Guidelines
- NZTA Monetised Benefits and Costs Manual (appraisal inputs)
- Austroads modelling guidance
Tools
- SIDRA Intersection / Networks
- Aimsun (microsimulation)
- Power BI
- Python / R
Relevant projects
Who leads this work
Frequently asked
How do I know whether I need SIDRA or Aimsun?
SIDRA is the right tool for intersection and network capacity and performance; Aimsun microsimulation earns its cost when vehicle interactions, queuing between closely-spaced intersections, or dynamic effects drive the answer. We recommend the lightest approach that actually answers your question — often that's SIDRA, sometimes it's both.
Can the modelling feed a business case?
Yes — that's most of what we do. We produce the option performance and sensitivity results the economic case needs, in a form that lines up with NZTA appraisal, so the modelling and the business case stay consistent.
Do you build dashboards, or just models?
Both. Where a council or NZTA needs results to live on — patronage, crash, network performance — we build Power BI dashboards and custom Python / R analysis on top of the model, so the insight is reusable rather than a one-off report.
Can you independently review someone else's model?
Yes. As an NZMUGS-member team we both build models and independently review third-party SIDRA and Aimsun models — checking the build, calibration and assumptions before the results are relied on.