Executive Summary

NewZealand’s (NZ) approach to Temporary Traffic Management (TTM), also known globally as work zone safety (WZS), is at a critical juncture. Traditionally, the design of TTM (planning how traffic and safety will be managed around activity on the road) has often been “bundled” with its physical delivery (on-site deployment of resources). This model, where a single entity often designs and implements TTM, introduces a conflict of interest that can inflate costs and compromise effectiveness.

The provider profiting from supplying traffic management resources often determines the quantum of those resources, creating an incentive for oversupply – more personnel and plant resulting in more cumbersome installation and removal of TTM than may be justified by actual risks. The result is an industry increasingly viewed by some as inefficient, where adherence to past norms or perceived ‘requirements’ has overshadowed the core goals of safety and effectiveness.

Decision-makers increasingly recognise that more TTM does not necessarily equate to safer outcomes. Despite a growing presence of traffic control measures, NZ has seen work zone deaths and serious injuries rise, indicating diminishing safety returns on investment. Public frustration, notably in Auckland with the “road cone mania” discourse and a subsequent EY report in 2024, has highlighted perceptions of inefficiency. The EY report suggested that prevailing regulations and commercial models can enable TTM contractors to “overkill” projects, potentially maximising disruption—and thus billable hours and equipment—for profit, sometimes beyond what a risk-based assessment deems necessary. This practice erodes public trust and impacts productivity through unnecessary congestion.

Internationally, jurisdictions like the UK have addressed similar issues by altering incentives using lane rental charges and fines for prolonged roadworks to discourage excessive disruption. The transition in NZ from the prescriptive Code of Practice for Temporary Traffic Management (CoPTTM) to the risk-based NZ Guide to TTM (NZGTTM) presents both an opportunity and a challenge. While offering flexibility, this shift, without robust independent oversight on TTM design, could inadvertently amplify the risk of oversupply, as decisions on TTM quantity become less constrained by a detailed rulebook and more reliant on risk assessments that could be influenced by commercial interests if not independently derived.

Decoupling the design of TTM from its physical delivery offers an opportunity to realign the industry with safety and efficiency. By engaging independent TTM designers early in the project lifecycle, project teams can develop risk-based, right-sized TTM plans untainted by the direct profit motives associated with implementation volume. Such plans focus on specific site hazards and explore innovative mitigation strategies—including doing less or doing things differently—to achieve the “lowest total risk”. Early integration of TTM planning enhances constructibility and safety in design, making traffic management a core project component. This aligns with international practices, such as in the United States, where comprehensive Transportation Management Plans are often developed during project design for major projects.

This white paper examines the case for separating TTM design from delivery in NZ. It defines the problems with the bundled model, particularly how the changing regulatory landscape might influence oversupply risks, and explores the associated cost implications, drawing on recent data indicating significant increases in TTM expenses. It discusses the benefits of an independent design process, from fulfilling legal duties under the Health and Safety at Work Act 2015 (HSWA) to achieving tangible safety and project improvements. The paper also provides international comparisons and outlines practical recommendations for implementing decoupled procurement, addressing potential barriers, and weighing the trade-offs. The goal is to present a balanced, evidence-based argument for reforming TTM practices, restoring focus on risk management, and removing perverse incentives to ensure TTM serves as an efficient, effective safety tool with public and industry confidence.

Problem Statement

The bundled procurement of TTM – where the same entity often designs the traffic management plan (TMP) and delivers the on-site setup – remains a common practice in NZ. This model embeds a fundamental conflict of interest. The party determining “how much” TTM is required also profits directly from the resources deployed – primarily the labour and plant (vehicles) hours on site. Three main factors drive TTM costs: (i) the base rates for personnel and plant, (ii) the duration the TTM is required, and (iii) the quantity of personnel and plant deployed. While base rates are subject to market forces, and duration is often linked to the work’s scope, the quantity of TTM resources is the most significant lever for cost and is where the conflict of interest has the most significant impact. For instance, adding just one extra TTM crew member for a 10-hour day at $35 per hour incurs a $350 cost. To achieve an equivalent $350 saving through base rate reduction for a crew member working 200 hours on a project, a rate decrease of $1.75 per hour would be necessary. This illustrates that decisions affecting the quantity of resources deployed have a far greater immediate cost impact than marginal adjustments to base rates.

This self-serving dynamic can lead to an oversupply of traffic management: excessive or overly conservative setups that extend beyond what a targeted, risk-based approach would objectively dictate. The symptoms are visible – extensive coning and prolonged speed restrictions, sometimes for minor works or during periods of inactivity. The 2024 EY report for Auckland Council found that prevailing rules could “allow providers to ‘overkill’ projects, profiting from having staff and equipment deployed for as long as possible”. In essence, inefficiency can be inadvertently rewarded.

The transition from the prescriptive CoPTTM to the risk-based NZGTTM, while intended to promote tailored and efficient TTM, introduces a new dimension to this problem. CoPTTM, despite its limitations, provided a relatively explicit baseline for TTM configurations, offering a framework against which TTM plans could be benchmarked. While oversupply was still possible under CoPTTM (e.g., by exceeding minimum specified resources), the NZGTTM’s emphasis on site-specific risk assessment grants TTM designers more discretion.

Suppose the TTM designer is also the TTM provider. In that case, there is an amplified risk that risk assessments might be reverse-engineered or skewed to justify greater quantities of TTM than necessary, especially if clients and principal contractors effectively outsource their responsibilities and rely heavily on the TTM subcontractor’s advice. Concerns have been voiced within the TTM industry about potential corner-cutting under a risk-based approach (“not doing enough TTM because CoPTTM is gone”). However, the converse risk – doing more TTM than is justified because the “rulebook” constraint is looser and the decision-maker profits from volume – is a less discussed but equally critical concern that decoupling seeks to address.

Beyond direct cost inefficiencies borne by clients, taxpayers, and road users, the bundled approach has broader negative impacts. Late integration of TTM into project planning means opportunities for safer, more efficient construction methodologies are missed. Safety in design principles, expected by HSWA 2015, is also compromised when TTM design is an afterthought. This can lead to risks mitigated by “brute force” on-site (more cones, more staff) rather than smarter upstream design choices.

The previous compliance-driven culture under CoPTTM encouraged a “follow the rulebook” mentality, sometimes leading contractors to offload TTM responsibility entirely. This, coupled with some rigid enforcement, reinforced a cycle of escalating TTM deployment. Worryingly, this proliferation of TTM has not correlated with improved safety. Analysis of NZ work zone crash data has indicated that “more people have been killed or seriously injured in work zones on NZ’s roads in the last 6 years than in the prior 14 years combined“, suggesting that simply deploying more conventional TTM is not addressing the safety problem effectively and may create new hazards or complacency.

Background and Context

TTM evolved in NZ under the CoPTTM, which, by its final edition, contained nearly 1,450 clauses. This prescriptive detail fostered a compliance-first mindset. As CoPTTM expanded, so did the TTM industry, leading to a situation where TTM could sometimes consume 10-15% or more of project costs on maintenance works by 2023-24.

The “road cone mania” outcry in Auckland, culminating in the 2024 EY report, highlighted public and political concerns. The report noted that “contractors have little incentive to work cheaper and faster”. It further suggested that under existing rules and regulations, “contractors [can be] incentivise[d] to cause maximum disruption to maximise profits”. While main contractors operate within a competitive tendering environment that should, in principle, penalise deliberate over-scoping or prolonged works that unnecessarily inflate overall project costs, the incentive structures identified by the EY report may apply more acutely within the TTM supply chain. Specifically, specialist TTM subcontractors, whose revenue is directly linked to the volume of personnel, plant, and duration of TTM deployed, can face a direct incentive to recommend or implement more extensive TTM. In a bundled model where the TTM subcontractor also designs the TTM, or where the main contractor lacks the specialist expertise or contractual levers to scrutinise TTM recommendations rigorously, these potentially inflated TTM costs can be passed on, or the TTM arrangements themselves may inadvertently enable or fail to penalise extended site occupation by the primary works.

This situation highlights a nuanced problem within the contracting chain rather than necessarily a universal behaviour by all main contractors, and it contrasts sharply with international practices, such as lane rental schemes in the UK, which financially incentivise minimising disruption across the entire delivery chain. The NZ Government Policy Statement (GPS) on Transport 2024 subsequently identified TTM inefficiency as an issue and introduced mandatory TTM cost reporting, creating momentum for reform.

Further context is provided by recent research into TTM costs. A December 2024 report by Beca for Electricity Networks Aotearoa (ENA) revealed alarming trends. Key findings from data spanning 2019-2024 include:

• A significant rise in the average cost of TTM per day, increasing by approximately 208% (around $1,631 per day in real terms) between 2019 and 2024. The forecast suggests a continued rise to a mid-point average of circa $2,945 per day by 2026.
• A strong positive correlation between project duration and TTM cost, where a tenfold increase in project duration could lead to an average increase of 153% to 399% in TTM costs.
• Dramatic increases in TTM costs per kilometre compared to the 2004 Commerce Commission ODV (Optimised Deprival Valuation) handbook figures, even after adjusting for inflation. For instance, Level 1 TTM for overhead lines saw an average cost of $30,296 per km in the 2019-2024 data, a 1794% increase from the NTI-adjusted 2004 ODV figure of $1,600 per km. TTM for Level 2 requirements with excavation in the carriageway rose to $177,416 per km, a 122% increase over the adjusted ODV figure.
• State Highway TTM costs per kilometre showed a particularly stark increase of 403% between 2019/2020 and 2024 in the analysed dataset.

These rising costs, coupled with evidence of an infrastructure sector slowdown and overseas buyers’ entry into the NZ TTM market in the last five years, suggest that the TTM sector is perceived as lucrative. If the volume of infrastructure work is not proportionally increasing, such profitability may stem from an increase in the cost and quantity of TTM per project rather than solely from an increased number of projects. This points towards the TTM supply potentially driving demand and cost, a dynamic that decoupling aims to correct.

The regulatory shift towards a risk-based approach is pivotal. WorkSafe NZ guidance (2022) and the NZ Transport Agency’s NZGTTM (replacing CoPTTM in late 2024) champion risk assessment over prescriptive rules. The NZGTTM emphasises identifying hazards, assessing risks, and applying the hierarchy of controls to achieve the “lowest total risk”. HSWA 2015 underpins this, requiring all PCBUs (Persons Conducting a Business or Undertaking) to ensure safety so far as reasonably practicable and consult, cooperate, and coordinate. This legal framework implicitly supports early TTM planning. HSWA’s duties on designers to ‘ensure designs are safe to build’ also align with incorporating TTM planning into the main project design phase.

Internationally, the UK’s model often involves TTM planning by engineers or specialists independent of the works contractor, alongside strong financial disincentives for disruption like daily fines up to £10,000 for overruns and lane rental charges up to £2,500 per day. While not mandating decoupling, these measures incentivise efficient TTM, often leading to expert, independent planning. Australia is also moving towards risk-based frameworks, with Queensland, for example, updating its TTM manuals in 2025 to integrate risk assessment. In the USA, federal regulations require Transportation Management Plans for federally-aided highway projects, often prepared by engineering consultants or DOT designers during project development, ensuring an owner/designer focus on safety and mobility.

This background—evolving TTM understanding, escalating costs, public pressure, policy shifts, and new risk-based guidelines—creates a compelling case for change in NZ.

Analysis and Discussion

Conflict of Interest and Oversupply in Bundled TTM

The conflict of interest in the bundled model is not merely theoretical. The Beca (2024) report’s findings of rapidly escalating TTM costs provide quantitative backing to concerns about supply-driven dynamics. The 208% increase in average TTM cost per day (2019-2024) outpaces general inflation and suggests systemic cost drivers beyond mere market adjustments for labour and plant. As the EY report for Auckland Council noted, under some current NZ rules, providers may “have little incentive to work cheaper and faster”. This can manifest as leaving TTM in place during inactive periods or extending closures, as disruption costs are largely externalised.

Defenders of the bundled model, such as some contractor groups, argue that safety obligations and client-approved plans drive TTM setups. While contractually, TTM plans are accepted by clients or their engineers, they often originate from the TTM provider who will implement them. This blurs the lines of objective assessment. Decoupling aims to clarify this by ensuring the design is genuinely independent, basing recommendations on assessed risk rather than a business model predicated on volume.

The Beca report’s data on TTM costs as a percentage of total project costs (Figure 7 in the Beca report shows this percentage decreases as total project cost increases) is instructive. While this is expected due to fixed TTM components, the sheer magnitude of baseline TTM costs (e.g., per day or km) remains a concern. The report’s finding that for every tenfold increase in project duration, TTM costs can rise by 153% to 399% (Figure 10, Beca report) further highlights how extended TTM deployment, incentivised under a bundled model without strong counter-incentives, directly escalates project expenditure.

Comparisons with international practices, such as London’s lane rental scheme leading to a 31% reduction in average work durations by utility companies, show that behaviours change when financial incentives are aligned with efficiency. The pressure to innovate for efficiency has been weaker in NZ’s traditional bundled model without such strong disincentives for occupation. If design remains coupled with delivery, shifting to a risk-based framework under NZGTTM could exacerbate this. Without the prescriptive (though sometimes cumbersome) checklist of CoPTTM, a TTM provider has more scope to define “necessary” TTM through their risk assessment. If this assessment is not independently scrutinised, it could justify more extensive and profitable setups.

Benefits of Independent TTM Design and Early Integration

Engaging an independent TTM designer early in the project lifecycle offers an objective, risk-based perspective. Their primary mandate is to appropriately protect workers and road users while facilitating project success by minimising undue impediments. Unfettered by operational delivery profits, they can explore a broader range of solutions, including those that eliminate or engineer out risks at the source.

Early integration is crucial for Safety in Design, a HSWA requirement. A TTM professional involved from the outset can identify and mitigate traffic-related hazards that civil designers might overlook. For example, instead of assuming prolonged lane closures for bridge maintenance access, early TTM input might lead to designing for alternative access (e.g., hanging scaffolds) or planning short, full road closures, potentially improving worker safety and reducing programme duration significantly.

This approach promotes right-sizing: implementing controls proportionate to risk. NZTA’s risk-based pilot projects have demonstrated this. For instance, some projects opted for full overnight or short-term full road closures, allowing works to be completed significantly faster and often more safely than under prolonged partial closures. These decisions, often counterintuitive to a “keep traffic flowing at all costs” mindset, are more readily proposed by a planner not financially tied to maximising the duration or extent of TTM deployment. That is not to say that road closures are “the answer,” but they do offer a mechanism for expedient work and reduced temporal risk under the right conditions.

Early TTM design facilitates better coordination among all PCBUs (client, principal contractor, and other stakeholders), fulfilling HSWA duties and preventing downstream conflicts. An independent designer can act as a neutral facilitator in these consultations. International guidance, like that from the Minnesota DOT, supports this, advocating for temporary traffic control concepts to be developed during preliminary design with cross-discipline collaboration. This allows for holistic planning, where TTM is not an add-on but integral to project methodology, potentially incorporating strategies like dynamic lane management or smart work zone technologies if justified by robust, independent analysis.

Case Studies: Risks of Bundled TTM vs. Benefits of Separation

NZ Case – “Road Cone Mania” in Auckland and the EY Report

The Auckland-centric ‘war on cones’ (2022 onwards) highlights the pitfalls of bundled TTM. Widespread complaints arose about excessive cones and prolonged lane closures for minor or inactive works. The EY report (2024) confirmed that contracts often lacked mechanisms to charge for road space occupation, meaning contractors faced few direct penalties for causing extended disruption. This environment, where TTM plans were often developed by those delivering the service, led to overly cautious or convenient (for the contractor) setups. Subsequent interventions by Auckland Transport, requiring more justification for TTM and piloting road occupation charges, reportedly led to contractors becoming more efficient, suggesting previous slack in the system. This case implies that independent scrutiny and altered incentives can drive positive change.

International Case – United Kingdom Utilities Coordination and Lane Rental

In the UK, lane rental schemes, while not direct decoupling mandates, illustrate how financial incentives drive optimal TTM planning. Faced with daily charges for road occupation, utility companies have re-evaluated their work methodologies, often engaging specialist traffic planning firms to design efficient TTM. This has led to strategies like coordinating multiple utility works within a single, well-planned full closure, significantly reducing the overall period of disruption compared to multiple, sequential works. This demonstrates that when the delivery party internalises the cost of TTM-induced disruption, they seek experts, often independent, who plan to minimise that cost, achieving better outcomes for the public. This functional separation of planning (to achieve efficiency) from delivery highlights the benefits transferable to a formal decoupling model.

These examples indicate that bundled approaches can lead to inefficiencies and public frustration, whereas independent, objective planning, often spurred by revised incentives, can foster innovative and more effective solutions.

Solutions and Recommendations

To achieve decoupling of TTM design from delivery, a multi-pronged approach is recommended:

1. Revise Procurement Models. Clients (e.g., NZTA, local councils, utility asset owners) should structure contracts to separate TTM planning from implementation. This could involve directly engaging TTM design consultants. Project tenders could feature distinct packages for “TTM Planning and Advisory Services” and “TTM Implementation”.
2. Embed TTM Design Early. Mandate that TTM considerations are integrated from the project concept/design phases. A preliminary TMP should be part of early project documentation (e.g., Detailed Business Case), with a detailed TMP by final design. This should be a prerequisite for approvals.
3. Clear Delineation of Roles. Define “TTM Designer” (responsible for risk assessment, TMP development, stakeholder liaison) versus “TTM Provider” (responsible for implementing the plan, real-time management, and site maintenance). Formal handovers and protocols are required for managing deviations from the approved TMP, ensuring the designer retains authority over the plan’s safety intent.
4. Strengthen Independent Review and Assurance. Establish peer review systems for complex TTM plans. To foster continuous improvement, incorporate data-driven validation by collecting and reviewing TTM performance data (disruption, incidents, public feedback).
5. Update Regulations and Guidance. NZTA and WorkSafe could explicitly recommend separation in publications like the NZGTTM or guidance on overlapping duties. Consider legislative or bylaw tweaks to formalise this. Pricing reforms like lane rental schemes can complement decoupling by making efficient design tangibly beneficial.
6. Industry Capacity Building. Invest in training and certifying TTM designers/planners as a distinct competency. Encourage existing TTM companies to adapt by offering planning services independently from delivery, with appropriate firewalls.
7. Pilot Projects and Gradual Scaling. Implement decoupling through pilot projects across various contexts. Monitor outcomes (cost, safety, satisfaction), document lessons, and use evidence to refine processes and build buy-in before wider rollout.
8. Collaborative Frameworks. Utilise delivery models like alliances or Early Contractor Involvement (ECI), where an independent TTM design lead is embedded within the project team, is co-equal with construction leads, and shares project goals.

The following table summarises the anticipated shift:

A critical recommendation involves addressing legal and contractual implications under HSWA, ensuring contracts mandate collaboration between the independent designer and the implementing contractor while affirming that all parties retain their safety duties.

Benefits, Risks, and Trade-Offs

Adopting a decoupled TTM approach offers significant benefits but also entails risks and trade-offs.

Benefits

• Improved Safety Outcomes. Focus on objective risk assessment and optimal control selection should lead to more effective TTM and, ultimately, a reduction in worksite incidents.
• Cost Efficiency and Right-Sizing. Avoids oversupply, potentially leading to significant cost savings (e.g., 10-30% on TTM in some estimates), aligning with GPS objectives for better value. The Beca (2024) report’s findings on current cost escalations underscore the potential for savings if inefficiencies are tackled. Shorter project durations also yield indirect economic benefits.
• Transparency and Accountability. A clearer division of responsibilities improves auditing capability and can enhance public trust.
• Better Compliance with Legal Duties. Facilitates HSWA upstream risk management and PCBU coordination.
• Innovation and Best Practice. Encourages designers to adopt innovative TTM methods and technologies focused on optimal solutions.

Risks and Challenges

• Industry Resistance and Transition Pains. Existing contractors/TTM companies may resist changes to established business models. Requires education, phasing, and strong leadership.
• Capacity and Capability Concerns. An initial shortage of skilled independent TTM designers could occur. Requires investment in training and capacity building. Clear procurement rules are needed to ensure genuine independence.
• Coordination Risk. Potential for miscommunication between designer and implementer. Requires robust protocols, designer availability, and collaborative engagement.
• Potential for Over-Conservative Design. Independent designers, to avoid liability, might become overly cautious. Requires balanced training, peer review, and performance monitoring to ensure right-sizing considers practicality and “total risk”.
• Cost of Independent Design Services. Direct consultancy fees for design need budgeting. This upfront cost is expected to be offset by implementation savings.

Trade-Offs

• Speed vs. Diligence. Adding a design step might slow deployment for urgent works, mitigated by standing arrangements or pre-approved emergency plans.
• Flexibility vs. Control. On-site adaptability by experienced crews must be balanced with adherence to the independently designed plan. Frameworks for pre-approved variations can help.
• Commercial Impact on TTM Firms. Some firms might see disruption. The sector may need to adapt to value-based models.

Conclusion

NZ’s TTM practices require transformation. Decoupling TTM design from delivery is crucial to resolving inherent conflicts of interest and systemic inefficiencies that contribute to rising costs and concerning safety trends. The current bundled model can incentivise oversupply, especially in an evolving risk-based regulatory environment without the CoPTTM’s prescriptive guardrails. An independent design function promotes a risk-based, right-sized approach that better aligns with international best practices and domestic legal obligations.

While challenges exist, including industry adaptation and capacity building, they are surmountable with strategic implementation. The potential rewards—safer work zones, reduced public disruption, and more cost-effective infrastructure delivery—are significant. This reform is not about cutting corners on safety; it is about enhancing safety and efficiency by placing critical design decisions in the hands of objective experts, free from the commercial pressures of implementation volume.

By implementing the recommendations outlined, NZ can modernise work zone management, ensuring TTM is effective and efficient and commands public confidence. The aim is a system where TTM is “right-sized” to risk, collaboratively approached, and uncompromising on genuine safety, addressing the excesses and inefficiencies of the past. This change will contribute to a more credible and effective TTM regime that benefits workers, road users, and the wider economy.

References

Beca Limited. (2024, December 4). Assessment of Costs of Carrying Out Works in the Road Corridor for Electricity Distribution Businesses – Report on Findings – Rev B. Prepared for Electricity Networks Aotearoa.

Civil Contractors NZ (Alan Pollard), “Road cone obsession distracts from better safety outcomes,” Media Release, 22 Jul 2024.

Dave Tilton, “The Self-Feeding Organism: How Temporary Traffic Management (TTM) Became Its Own Industry – And Why That Must Change,” LinkedIn Pulse, Dec 10, 2024.

Dave Tilton, “The Unmet Promise of TTM: 20 Years of NZ Work Zone Crash Data,” LinkedIn Pulse, Feb 9, 2025.

Ernst & Young. (2024, July). Report on Auckland Temporary Traffic Management Practices (Hypothetical title based on text references, actual title may vary). Commissioned by Auckland Council.

Federal Highway Administration (US), “Work Zone Traffic Management – FHWA Operations,” (Work Zone Safety and Mobility Rule), (accessed 2025).

ITS International, “Government blitz on ‘disruptive roadworks’ causing traffic jams in UK,” Jan 17, 2024.

Minnesota DOT, “Project Development: Work Zone/Temporary Traffic Control Guidance,” (accessed 2025).

1News Report, “Auckland road cone report: ‘Maximum disruption — maximise profit’,” July 22, 2024.

TransportTalk, “Mayor calls for end to road cone’ mania’, welcomes EY report,” July 23, 2024.

Waka Kotahi NZTA, “Examples of efficient and effective TTM,” 2024.

Waka Kotahi NZTA, “Rolling out the NZGTTM – risk-based approach pilots,” 2024.

WorkSafe NZ, “Introduction to the Health and Safety at Work Act 2015 – Special Guide,” (section 3.8 Overlapping duties).

WorkSafe NZ / NZTA, “NZ Guide to Temporary Traffic Management (NZGTTM),” 2023.