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Technical bulletins

7 High Productivity and Overweight Permit attributes checks

Memo 70a – 28 Feb 2013


On 1 May 2010 Amendment 5 to Land Transport Rule; Vehicle Dimensions and Mass (Rule 41001/5) came into force. This amendment had the effect of allowing High Productivity Motor Vehicles (HPMV) to be longer and/or heavier than a standard vehicle combination, without being wider or higher.

HPMV vehicle approval requires operators to apply for a permit. As part of the application process, the applicant is required to confirm that their vehicle combination is technically capable of carrying the heavier load within its certifications. Audits on the first 100 applications have shown that many applicants have made errors, applying for masses higher than their vehicle or component capacity or certifications, particularly brake code mass.

These errors have created a considerable amount of work for the Agency’s permit and technical staff resulting in long delays in the issuing of permits.

Vehicle attributes check

In light of this the Agency will no longer undertake the process of reviewing the applications so any applications without a properly filled out attributes sheet signed by an approved HV Certifier will have them returned unprocessed. Operators must have their vehicle combination’s suitability assessed by a NZTA appointed HV certifier with either the chassis (HVEC or HVCD) or brakes (HVEK or HVKD) categories.

The Transport Agency has agreed to accept this assessment by the HV certifier on production, on letterhead, of a correctly filled out vehicle attributes sheet from the certifier confirming that the vehicles in a HPMV application comply with all the requirements of the permit application. Technical bulletin 12 shows a sample form.

Where the certifier does not have the categories to confirm specific aspects of compliance or certification they must contact a certifier with the required category or categories to confirm compliance. Such confirmation shall be on letterhead and be kept on file by the recording certifier. This information from another certifier will indemnify the recording certifier against any claims if the information provided is false. While this activity does not require certification with an LT400 the certifier must have a PDS for the task. It will be included in their review process and the certifier will be held accountable. It is the responsibility of the certifier signing the Attributes Sheet to ensure that all required information is included. Only one attributes sheet will be accepted per vehicle with each application and only one vehicle is allowed per attributes sheet (except for 50Max which are dedicated combinations). Sheets must be complete for the permit being applied for or they will not be accepted

Once the form is correctly filled out the operator can then use it to support an HPMV application. The certifier is not held responsible if the operator, while using the form supplied by the certifier, makes an application for a HPMV permit which is not supported by the information recorded on the vehicle attributes form or where uncertified modifications have been made to the vehicle unless the certifier has been involved in such modifications.

Examples of what must be verified are:

  • Vehicle identity
  • Towing connections are appropriately certified for the weight to be carried
  • Brakes, where appropriate, brake coding verified, including brake code mass. Due to the critical nature of brake capability and the amount of creep seen in brake coded vehicles brake components critical to brake coding such as ratio valves must be verified
  • Electronic braking systems, including electronic stability control and roll stability control, are activated on settings appropriate for use.
  • Where applicable SRT is verified and operational limits confirmed.

Note that dimensional accuracy is the responsibility of the operator and is based on laden weights as checked by the CVIU at roadside. These dimensions may be the subject of roadside checks by the Police, CVIU or NZTA Transport Officers.

Build data may be used to fill out an attributes sheet but, if the vehicle is no longer under the control of the manufacturer then the accuracy of such data must be confirmed by a physical check or by receipt of a signed declaration from the operator stating that the vehicle has not been modified since manufacture or since the most recent certification, in any way that may affect the information presented on the attributes sheet. The certifier must keep this declaration with the PDS for the job. For other vehicles, where build data is not being used to provide information, a physical inspection of the vehicle will be necessary to ensure accuracy and confirm that no required attributes, such as brakes, have been modified. An attributes sheet may be reused for subsequent applications as long as the certifier who has signed it can confirm that there has been no change to any of the items featured on the attributes sheet or the operator makes a declaration that there have been no modifications which may affect the information presented on the attributes sheet.


Whether the vehicle is required to have an SRT of 0.35 (all trailers) or 0.4 (trailers without EBS/RSC) then that must be stated in a load v height matrix. Where the load is a closed container an SRT will only be accepted if it specifies uniform density. Mixed freight may only be used where the load is visible and the status can be verified.

Overweight permits

Similarly the changes to the VDAM Rule have also had the effect of focusing attention on the overweight permit (Opermit) process previously controlled solely by Transit with no access to vehicle information on Landata. Following the merger of Transit with LTNZ and the creation of the NZTA, which gave the permit staff access to Landata, the many inconsistencies in these Opermit applications have been highlighted so again operators are being required to verify vehicle details before permits are issued. Once again, this can be done in two ways; by waiting for the NZTA to verify details held, causing considerable delays for, often time sensitive, applications, or have those details independently verified by a HVS certifier with the ‘chassis’ category including noting where a vehicle has multiple chassis ratings and any conditions that may be attached such as speed limitations. It must be noted that where a vehicle may be used in a ‘pusher’ capacity not only must the GCM of it and the towing vehicle be cumulatively capable of supporting the total load, but the ‘pusher’ tow connection (front drawbeam) must be certified like any other drawbeam and capable of supporting its share of the load. It may therefore, be a limiting value for a combination where a pusher vehicle is proposed.

The same requirements as for the HPMV permit process are in force. A sample form is attached and these can be prepared for the operator and supplied as required with each permit application provided that there are no subsequent modifications which may affect the accuracy of the permit application

These attributes sheets from certifiers are accepted in lieu of an NZTA A&U approval as A&U will no longer carry out these attributes checks except for audit checks which will be carried out on both certifiers and operators.

It is important to note that the Permit Issuing Officers (PIO) have been tasked to check that the Attributes Sheets support the applications in that the attributes sheets list the design limits and the applied for mass should not exceed the lowest of these. Also, if the trailer does not have roll stability, then the 0.4 SRT requirement will be required to have a load height stated which will be noted as a restriction as a condition of the permit.

Note: Where there is a conflict between the data found during the physical selection and the data recorded on Landata the accuracy of the physical data must be confirmed and compared to the original build data and any differences recorded and reported to the NZTA so records can be updated and any missing certifications can be addressed.

The same requirements on certifiers as for the HPMV permit process are in force.