50MAX – information for road controlling authorities

The increased payloads of 50MAX means more efficient freight movement – this can lead to economic benefits for producers, customers and our communities.

Because 50MAX trucks have one more axle than conventional 44-tonne trucks, the overall truck load is spread further and there is no additional wear on roads per tonne of freight.

This page provides information for road controlling authorities (RCAs) about what they need to know about 50MAX and how to work with Waka Kotahi NZ Transport Agency on this initiative.

Assessing local road structures for 50MAX vehicles

Waka Kotahi has appointed regional coordinators across the country to liaise directly with RCAs for the implementation of 50MAX. Their aim is to assist RCAs and to work through any issues that might arise.

A key feature of the 50MAX implementation is to understand the load capacity of local road bridges. Waka Kotahi will work with RCAs to provide guidance on bridges that might inhibit travel for 50MAX vehicles in their regions.

Waka Kotahi has assessed restrictive bridges on state highways and these can be seen on the maps below.

What Waka Kotahi seeks from road controlling authorities

Waka Kotahi requests that all participating RCAs review their bridge stock and advise of any bridge restrictions for 50MAX vehicles.

These bridges will be off limits to 50MAX and will be plotted on maps to graphically show these structures as ‘restrictions’, and that operators are not permitted to cross them.

To assist RCAs with this process, a technical guidance document has been prepared that provides information on the assessment of bridges.

How this will be done

  • Using the guidance note, RCAs (or their consultant) will screen and classify their bridges to determine whether 50MAX loading can be safely supported. Further technical query support is available as noted below.

  • RCAs should complete the bridge restriction register. Please refer to the resources section below. This spreadsheet has technical and GPS mapping data to help with completing the register.

It is expected that the majority of bridges will be able to be quickly screened. There may be a small number of bridges where some analysis is required. Therefore the screening, completion of the register and forwarding of results needs to be done in two phases:

  • Phase 1: Initial screening. Use the guidance document procedures. Any bridges considered to need analysis should be included as restrictive bridges.
  • Phase 2: Analysis required. Analysis, where appropriate, may allow some restrictive bridges to be removed from the register.

Prepare and review map

On completion of the Phase 1 screening, forward the register to your 50MAX regional coordinator below so that the map data can be plotted.

Following preparation of permitting maps, these will be provided to the RCA for confirmation.

Future updates

Where future changes to permitting maps are required as a result of changes in bridge capacity, or further analysis; updates are to be provided to your 50MAX regional coordinator.

Contacts for technical guidance

Waka Kotahi has nominated the following contacts for 50MAX:

Local road bridge technical guidance for North Island

Andrew Ball

Associate – Structural Engineering
07 577 1128

Local road bridge technical guidance for South Island

Jeremy Waldin

Senior Bridge Engineer
Opus International Consultants Ltd
03 363 5537



Geospatial Analyst
Waka Kotahi NZ Transport Agency
04 894 5495

Resources and reports

Business case for lower bound high productivity motor vehicles

This 2012 report addresses the demand for heavy vehicles to go anywhere on the network with increased payloads, with no increased impact on bridge and pavement infrastructure. The report discusses the benefits for operators, the wider benefits for the customers, public and the country’s economy, and cost analyses. It predicts that there will be significantly increased freight productivity.

Read the business case [PDF, 943 KB]

Assessment of HPMV load limits for bridge loadings

This technical report was initially prepared in late 2011 for the assessment of load limits for bridges for full and limited HPMVs using the Transport Agency’s guidance maps for HPMVs. In September 2012 the report was modified for lower bound loading limits. The report also provides information about the assessment of bridges and a guide to those applicants seeking 50MAX HPMV permits.

Read the report on HPMV load limits for bridges [PDF, 372 KB]

Analysis of pavements

This report reviews the new 50MAX HPMV pro-forma vehicles and assesses whether the loading impact on the pavement is neutral when compared with the existing heavy vehicle traffic fleet. It also provides an assessment of the pavement effects based on loading impacts.

Read the report: Lower bound high productivity motor vehicles (LBHPMV): effects on existing pavements in New Zealand [PDF, 35 KB]

Further calculations were carried out to demonstrate the effect of the introduction of 50MAX HPMVs on typical rural roads in the Waikato and Bay of Plenty.

Read pavement impacts of 50MAX HPMVs on rural roads in the Waikato and Bay of Plenty [PDF, 190 KB]

50MAX HPMV vehicle configurations

The 2010 amendments to the Vehicle Dimensions and Mass (VDM) rule provided for heavy vehicles to operate (with a permit) at sizes and weights above the standard legal maximum, on routes where the infrastructure was capable of handling them. The provision of the large vehicles was aimed at increased productivity. The vehicles were designated as HPMVs.

To help with the uptake of HPMVs we have promoted the development of a pro forma HPMV design so that the vehicles can achieve the same low speed turning performance (or better) than the worst case standard legal vehicle. Therefore the road space requirements of the pro-forma designs are no greater than those of existing standard dimension vehicles. At standard legal weights, vehicles meeting these designs can be permitted for general access. At high weights a route assessment is needed to ensure that the infrastructure can cope.

This report sets out specific details about the configurations and specifications for 50MAX HPMV.

Read the Lower bound HPMVs – vehicle configurations report [PDF, 1.2 MB]

Brief report on off-tracking

When a combination vehicle travels along the road, the trailers do not follow exactly in the path of the truck. The offset distance between the path of the axles at the rear of the rear trailer and the path of the steer axle of the truck is called the off-tracking. This report explains and compares the three types of off-tracking performance of 23-metre HPMVs with that of standard legal maximum-sized vehicle for some representative turns.

Technical report on off-tracking [PDF, 280 KB]

Frequently asked questions

What is 50MAX?

50MAX is a new generation of truck that allows for safe and more efficient transport of freight goods. 50MAX trucks are slightly longer than standard 44-tonne vehicles, have an additional axle (9 in total) and can have a total weight of up to 50 tonnes.

What role do local authorities have in permitting 50MAX trucks?

Most road controlling authorities in New Zealand have signed a memorandum of understanding with the NZ Transport Agency, delegating the agency to issue 50MAX permits for roads in their region. These local authorities work with the Transport Agency to ensure any restricted roads or structures are clearly marked on the interactive map(external link) used by 50MAX operators.

Some road controlling authorities are still in discussions with the Transport Agency about permit delegations, while some others have decided to issue their own permits.

Won't 50MAX damage roads that aren't built for that size of truck?

No. Because 50MAX trucks have one more axle than conventional 44-tonne trucks, the overall truck load is spread further and there is no additional wear on roads per tonne of freight. Peer-reviewed studies of the technical aspects around 50MAX have shown there is no more impact on pavements than a Class 1 vehicle.

Are 50MAX trucks replacing the standard 44-tonne trucks?

No. 50MAX is an option for industry to use if they choose. It gives operators another option to carry increased payloads on parts of the network that, while economically important to New Zealand, are unable to carry high productivity motor vehicles (HPMVs).

What are the benefits at a regional level?

The increased payloads of 50MAX means more efficient freight movement. This can lead to economic benefits for producers, customers and our communities. Detailed information on the economic benefits is available in the business case in the Resources and reports section above.

What is being done to ensure the safety of 50MAX trucks?

50MAX trucks can improve road safety because of the reduction in truck trips to move the same amount of freight – fewer trucks on the road will mean a reduction in the crash risk. 50MAX trucks must meet the same high safety standards as other HPMVs, including increased resistance to roll over and the inclusion of electronic braking systems. A number of operators are investing in speed limiting, GPS monitoring, weight load cells, electronic stability control, electronic road-user charges and other safety measures. We recommend that all road transport operators consider the use of such available technology.

How can I find out more about 50MAX?

You can email info50max@nzta.govt.nz or call us on 0800 699 000.