If you've heard the term "risk-based TMP" and aren't entirely sure what it means in practice, you're not alone. The shift from CoPTTM to the NZGTTM has introduced a new way of thinking about Traffic Management Plans — and for many contractors, it requires a genuine change in how you approach drawing and submitting a TMP.
This guide explains what a risk-based TMP actually is, how it differs from what you've done before, and what it means for your day-to-day work.
The Old Way: Prescriptive TTM
Under CoPTTM, the approach was largely prescriptive. You looked up your road classification, your speed environment, your activity type — and CoPTTM told you exactly what devices to use, where to place them, and what your setup needed to look like.
It was straightforward to follow, but it also meant that a simple pothole repair on a quiet rural road might require the same paperwork and device setup as a more complex job in a similar category — even if the actual risk was much lower.
The New Way: Risk-Based TTM
Under NZGTTM, you start with the risks, not the rules.
Before you design your TTM setup, you're expected to ask: what are the actual risks at this specific site? Who could be harmed — workers, pedestrians, cyclists, motorists? How likely is that harm, and how severe could it be?
Your TTM setup — and your TMP drawing — should then reflect the controls you've chosen to manage those risks. The setup needs to be proportionate to the risk, not just compliant with a checklist.
This is what "risk-based" means: your decisions are driven by the hazards at your specific site, not by a standard template.
What Does This Mean for Your TMP Drawing?
Your TMP drawing is still a core part of the process — and under NZGTTM, it needs to clearly show how your layout addresses the identified risks.
A good NZGTTM TMP drawing will:
- Clearly show the work area, exclusion zones, and traffic paths
- Reflect the actual site conditions (not just a generic layout)
- Show device placement that makes sense for the specific risks identified
- Be accompanied by a risk assessment that explains the thinking behind the setup
The drawing and the risk assessment work together. One without the other isn't enough.
A Practical Example
Under CoPTTM, a footpath closure might require closing a long section of footpath for the full day, with a standard pedestrian diversion regardless of the actual work location.
Under NZGTTM, you might instead use a moving closure that follows the work — reducing the footprint, minimising pedestrian disruption, and actually lowering net risk by reducing the area where people are exposed to the hazard.
Both approaches involve a TMP. But the NZGTTM approach requires you to think through the risk first, then design the solution around it.
The Responsibility Shift
The risk-based approach puts more responsibility on contractors. As a PCBU under the Health and Safety at Work Act 2015, you're accountable for identifying and managing the risks at your worksite — not just following instructions.
This means your TMP is no longer just a compliance document. It's evidence that you've done your due diligence: that you've thought about what could go wrong, and that your setup is designed to prevent it.
Getting Started
If you're new to risk-based TMPs, NZTA has a library of resources and example forms at their NZGTTM TTM Library. Your local RCA may also have guidance on what they expect to see in a NZGTTM submission.
The most important thing is to start practising the risk-first mindset — identify the hazards, assess the risks, then design your TTM setup to manage them. Your TMP drawing follows from that process, not the other way around.
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