Traffic & Transport

The figure in the application material is approximately 3,000 vehicle movements a day, generated by 1,200 new dwellings at Arrow Junction. It is the single most portable number in this proposal, and also the most easily misread — so it is worth being precise about what it counts before arguing about what it does.

What a movement is

A vehicle movement is one vehicle travelling in one direction past a point. A household that leaves for work and comes home generates two. A school run out and back generates two more. A delivery van that arrives and departs generates two. Roughly 3,000 movements a day is therefore not 3,000 cars and not 3,000 journeys; it is the daily total of arrivals and departures attributable to the development.

That distinction cuts both ways, and we say so plainly: it means the figure is smaller than a careless reading suggests, and it also means the figure is an average of a day that is not average. Traffic does not arrive at a constant rate between midnight and midnight. It concentrates.

The daily total is the applicant’s own measure of the scale of change. The question that decides the effect is not the daily total. It is what happens in the busiest hours, at the worst locations, in the worst conditions — and that is the question the record has not yet answered in public.

Where the movements go

Arrow Junction sits where three quite different pieces of road network meet, and each one absorbs additional traffic differently.

State Highway 6

SH6 is the strategic route through the area. It carries long-distance freight, tourist traffic, and the daily commuting load of a district where most people have to travel to get anywhere. Traffic generated at Arrow Junction does not stay local; a large share of it joins SH6 and travels on it. Adding a development’s worth of movements to a state highway is not the same problem as adding them to a suburban street, because the highway is already doing several jobs at once and has limited room to be widened or re-routed through this landscape.

Gibbston Valley Road

Gibbston Valley Road serves a rural valley with a working land use and a visitor economy attached to it. Its function, geometry and the expectations of the people who use it are rural. A road built for that role does not become a distributor road for 1,200 dwellings by being renamed. Any increase here is a change in the kind of road it is, not only in the number of vehicles on it.

The Crown Range Road approach

The Crown Range Road approach is the alpine route. It is the most exposed of the three to weather, grade and seasonal conditions, and it is the one where a marginal increase in traffic interacts with the least forgiving geometry. Route choice matters here: when the main route is congested, drivers redistribute, and redistribution onto an alpine road is not a neutral outcome.

Where it accumulates

Movements generated across 1,200 dwellings do not stay dispersed. They converge. Every one of them passes through the development’s own access and its intersection with the wider network, because that is the only way in and out. Whatever the daily average, that point carries the whole of it.

This is why an intersection is the right unit of analysis and a daily total is not. An intersection has a finite capacity. When demand approaches that capacity, delay does not rise in proportion — it rises sharply, and queues begin to form and then to persist. The effects that follow are the ones residents actually experience:

• Queuing on the approach to the access, and on the through-route past it.
• Delay for traffic that has nothing to do with the development but shares the junction.
• Reduced gaps for right-turning and crossing movements, which is where safety risk concentrates at a rural intersection.
• Redistribution of drivers onto alternative routes — including the Crown Range Road approach — as they avoid the delay.
• Pressure for further roading works, which have their own landscape and cost consequences and are not usually counted in the effects of the development that caused them.

None of that is speculative in principle. It is how intersections behave. What is genuinely uncertain is the magnitude here, and the magnitude is what the modelling is for.

What the applicant says

The application material puts the generation figure at approximately 3,000 vehicle movements a day. That is an applicant-supplied estimate produced for the application, and it is properly classified as such. We are not disputing it, and we have not verified it independently — we could not, because the underlying traffic assessment, its trip-rate assumptions and its distribution assumptions are not in front of us.

• The traffic assessment supporting the ~3,000 movements a day figure — [Source to be added]
• The intersection modelling for the Ridgeburn access and its junction with the wider network — [Source to be added]
• Any road safety audit of the proposed access arrangement — [Source to be added]
• The road controlling authority’s and state highway manager’s responses to the application — [Source to be added]

What has not been answered

These are the questions we are asking, and they are the questions that would change our assessment if they were answered.

• Peak, not average. What is the generation in the busiest hour, and how does the access intersection perform at that hour?
• Distribution. What proportion of movements is assumed to turn onto SH6, onto Gibbston Valley Road, and toward the Crown Range Road approach, and on what basis?
• Trip rates. What household trip rate was assumed, and does it reflect a district where car ownership and travel distances are high and public transport is limited?
• Staging. Is the figure the effect of the completed development, or of a stage of it? A partly built development generates less traffic and proves nothing about the finished one.
• Cumulative effect. Is the assessment against today’s traffic, or against traffic that already includes other consented and proposed growth in the same corridor?
• Safety. What is the crash history of the affected intersections, and what does the assessment predict for it? — [Source to be added]
• Who pays. What roading and intersection works are required, when, and at whose cost?
• Everything that is not a car. What provision is made for walking, cycling and public transport, and what happens to the figure if none of it is used?

The day simulation, and why it is not here yet

A day-in-the-life simulation of this corridor is planned and is not built. We could publish an animation tomorrow; we are not going to, because a picture of traffic is a claim about traffic, and an unsourced picture is the most persuasive kind of overstatement there is.

When it ships it will disclose its assumptions before it shows anything: the trip rates used, the directional split assumed, the peak-hour factor, the base traffic it is added to, the intersection form it models, and the source of each. If a number in that list cannot be sourced, it will be shown carrying a gap label rather than quietly averaged into the result.

Our position

Roughly 3,000 movements a day is a large, permanent change to a rural junction and to three roads that are each already doing a difficult job. We think the burden is on the applicant to show, with published modelling, that the network can carry it safely at peak — not on the public to show that it cannot. Until that modelling is public, the traffic case for this development is unproven, and the figure that is public describes the size of the problem rather than its solution.

Evidence statement

Classification: Analysis

Status: Analysis of an applicant-supplied estimate. The ~3,000 movements a day figure is the applicant’s; the reasoning about where it accumulates is ours, and is not a traffic model.

Author: Ridgeburn Press · Evidence Desk

Last reviewed: 16 September 2026

Sources

1. Application material — traffic generation estimate (approximately 3,000 vehicle movements per day), applicant — [Source to be added]
2. Integrated transport assessment and intersection modelling, applicant’s traffic engineer — [Source to be added]
3. Road controlling authority and state highway manager responses — [Source to be added]

Assumptions

• That the ~3,000 figure describes the completed 1,200-dwelling development rather than a stage of it — [Awaiting client evidence]
• That movements distribute across SH6, Gibbston Valley Road and the Crown Range Road approach; the assumed split is not published — [Source to be added]
• That the figure is a daily total and not a peak-hour figure.

What is not established

• Peak-hour generation, or the performance of the access intersection at peak.
• The trip rates and directional split underlying the daily total.
• Whether the assessment is cumulative with other consented and proposed growth in the same corridor.
• The crash history of the affected intersections and the predicted change to it.
• What roading works are required, when, and at whose cost.

Right of response

Ridgeburn Limited, Queenstown Lakes District Council and any person named here may respond in full. How to respond.