Risk-Based Temporary Traffic Management: How AGTTM Changes the Game

Introduction

Temporary Traffic Management (TTM) has long relied on standard templates and generic setups. But under the Austroads Guide to Temporary Traffic Management (AGTTM), the industry is undergoing a major shift: from default layouts to a structured risk-based planning model.

If you’re still starting your TMP with the question, "Which layout should I use?" — it’s time to reframe your thinking.

What is the Risk-Based Approach?

At the heart of AGTTM is a risk management process tailored for TTM, designed to:

• Eliminate or minimise hazards to road workers and road users

• Adapt to the specific circumstances of the site

• Provide a clear justification for planning decisions

Key Reference: AGTTM10-21, Section 2.4.1: A Model Risk Management Process

Step-by-Step Breakdown

The AGTTM's model includes five distinct steps:

Step 1: Determine Site Risk Rating

Use a matrix (likelihood x consequence) to classify the risk level of the worksite. Factors may include traffic speed, road user volume, road classification, and proximity to live traffic.

Step 2: Define Required Level of Planning

Higher-risk sites require more comprehensive planning and approval pathways. This may trigger the need for:

• A site-specific TMP

• Additional consultation with road authorities

• Enhanced mitigation strategies

Key Reference: AGTTM10-21, Section 2.4.2

Step 3: Assess On-Site Risks

This involves identifying dynamic and residual hazards, such as turning vehicles, pedestrian conflicts, or limited sight distance.

Step 4: Apply Hierarchy of Control

Eliminate > Substitute > Engineer > Admin > PPE. Control measures should be selected in that order of effectiveness.

Tip: Portable traffic control devices or attenuators should be viewed as supporting controls — not primary safety solutions.

Step 5: Document and Monitor

All risk assessments, controls, and revisions must be documented within the TMP and monitored throughout the project lifecycle.

Common Pitfalls (and How to Avoid Them)

• Mistaking road category for risk level: A Category 1 road isn’t automatically high risk if traffic volume is low.

• Using sample layouts as a shortcut: These are references, not prescriptions.

• Skipping residual risk: Even the best controls require fallback planning.

Why This Matters

TTM is about more than cones and signs. AGTTM asks the industry to treat every site like it matters — because it does.

Risk-based planning:

• Aligns with WHS legislation

• Supports innovation and flexibility

• Improves safety outcomes and audit defensibility

Final Word

The shift to a risk-based approach isn’t just regulatory lip service — it’s a smarter, safer way to manage worksites. And it puts the focus back where it belongs: on the unique risks of the real world.

Start your next TMP not with a layout, but with a question: What could go wrong — and how can we prevent it?