Frequently asked questions about type approval of tyre-stud combinations

Approval may be granted only to the manufacturer who has been granted tyre type approval pursuant to UNECE Regulation No. 30 or 54

Type approval tests can be carried out by recognised experts approved by Traficom

An over-run-test measures how much wear studded tyres cause by driving a tyre over test stones the number of times required by Traficom Regulation, after which the test stones are weighed for mass lost. Limit values for weight loss are established according to the load rating.

The over-run test is carried out in accordance with Traficom Regulation.

For more information about the requirements for a recognised expert and how to apply to become a recognised expert see the memorandum written by Traficom, available on the Traficom website.

In the phase A, testing in over-run tests is carried out by load capacity index categories as follows:

Passenger car tyre (class C1):

• under 600 kg (LI < 90)
• 600 kg – 800 kg (90 ≤ LI ≤ 100) and
• over 800 kg (LI> 100). This category can also include SUV tyres. If the tyre model and structure is the same as in a passenger car tyre model, they can be regarded as a single type.

In phase A+, the over-run test will test one or more tyre sizes representing the entire tyre type considered the most unfavourable in terms of road wear. 

Tyres for light trucks (class C2), such as commercial vehicles or vans, are tested separately and are always regarded as a different type than passenger car tyres.

There is no limit to the number of studs in a studded tyre that has been type approved on the basis of an over-run-test. In phase A, the number of studs per metre of tyre rolling circumference is recorded for the tyre size selected from the tyre load capacity index category (see previous question) for over-run-testing. The number of studs, as referred to above, defines the maximum number of studs for all tyres in the same load capacity index categories.

In phase A+, the number of studs per metre of tyre rolling circumference has been recorded in the tyre size list for each tyre type, which the manufacturer has submitted to Traficom at the application phase.

 As per the previous answer, in phase A the number of studs per metre of tyre rolling circumference cannot be greater than the number of studs in the tyre tested for a given load capacity index category. If the number of studs per metre of tyre rolling circumference is to be increased, a new over-run-test must be carried out and an extension to the scope of the type approval applied for. The number of studs per metre of tyre rolling circumference is rounded up to the next whole number. If there are changes in the number of studs in phase A+ tyres, the manufacturer must assess whether the most unfavourable tyre size for the over-run test changes and follow the instructions provided.

To avoid differences in the interpretation of the tyre rolling circumference, the definition of the theoretical tyre rolling circumference in the Engineering Design Information manual published by ETRTO is applied, using the total diameter design dimensions given in the ETRTO Standards Manual in the calculations.

This information can be found in section 6 of the Traficom Regulation. The documents required for a new type approval application include at least a completed information document form with a list of companies that perform the studding and their locations (Annex 4 to the Regulation), a test report by a recognised expert, a type approval certificate in accordance with UNECE Regulation no. 30 or 54 for the tested tyre size, a drawing of the tyre’s tread pattern model and stud models. These are to be delivered to Traficom at: Finnish Transport and Communications Agency Traficom, Type Approval Unit, P.O. Box 320, FI-00059 TRAFICOM. 

If the manufacturer is located in a country other than Finland, a representation agreement of the manufacturer’s representative in Finland is required. In addition, a list of tyre sizes is required when applying for the phase A+ approval.

The manufacturer must have a documented quality management system that meets at least the requirements of the “CoP Regulation” (Monitoring procedures to ensure the conformity of production of a vehicle, system, component, separate technical unit, part or equipment). In connection with CoP monitoring, Traficom checks the documentation of the entire quality management system. 

The manufacturer must submit a written production control plan to Traficom. 

If the manufacturer is located in a country other than Finland, an authorisation for the manufacturer’s representative located in Finland is required. The authorisation must be submitted to Traficom. 

The manufacturer must conclude an agreement on CoP monitoring with Traficom. The contract documents can be found on Traficom’s CoP website.

A written production control plan refers to a documented description of the procedures and inspections that can be used to ensure that the product continues to meet the requirements for type approval throughout the period of validity of the type approval. 

The written production control plan shall cover all production sites of the product to be type approved. In the case of type approval of a tyre-stud combination, the production site means the location where the tyres are studded.

You will find the requirements for a written production control plan in section 4 of Traficom’s CoP Regulation

For more detailed instructions and examples related to the production control plan, see the instructions  on the Traficom CoP website.

Section 2, subsection 48 of the Vehicles Act defines as the manufacturer’s representative a party “authorised by the manufacturer of the vehicle, system, component, a separate technical unit, part or equipment to represent itself in relation to the approval authorities and market surveillance authorities and to act on its behalf in matters relating to type approval or individual approval”.

The authorisation must state if the representative has the following obligations/rights:

• The representative responds to requests for clarification related to the type approval application
• The representative transmits the type approval documentation to the type approval applicant 
• The representative shall be entitled to have access to the type approvals granted to the type approval applicant and the appendices to them
• The representative acts as a contact point in CoP matters

Other rights and obligations, such as matters related to invoicing, can also be added to the list as necessary.

An authorisation template can be found on Traficom’s CoP website.

Whenever there are technical changes to the tyre-stud combination or the data in the type approval certificate needs to be updated.

According to the Traficom Regulation TRAFICOM/383441/03.04.03.00/2022 concerning the technical requirements for studded tyres for vehicles, the stud model, as described under paragraph 11) of section 2 “Definitions”, cannot be changed in a tyre-stud combination. Changes to the stud model are only permitted when the name, dimensions, mass or materials of the stud model do not change. The stud manufacturer can be replaced or new manufacturers added by applying for an extension to the type approval. If the change affects the characteristics mentioned in the definition of the type of tyre-stud combination, such as the name, dimensions, mass or materials of the stud model, a new type approval must be applied for the tyre-stud combination. 

Traficom has outlined that type approvals granted under the repealed Decree 408/2003 can only be extended with non-technical amendments. This means that changes related to tyres or studs can no longer be extended under these type approvals. The permitted changes concern written, non-technical information provided on the type-approval certificate, such as the manufacturer’s name or address information, facilities in which the tyres are studded etc. When replacing or adding a stud manufacturer, the instructions provided under the definition of tyre-stud combination in section 2, paragraph 11, of the Regulation TRAFICOM/383441/03.03.00/2022 shall be complied with.

The requirements of the “CoP Regulation” shall apply to manufacturers of type-approved studs and tyre-stud combinations starting from 15 March 2024. The Regulation contains general requirements related to monitoring conformity of production. 

The separate testing requirements of the “Stud Regulation” (paragraphs 3 and 4 of Regulation 4.3) shall apply to new type approvals as of 1 January 2025.

According to section 7, paragraph 5 of Traficom Regulation TRAFICOM/383441/03.04.03.00/2022, all tyres manufactured on or after 1 January 2025 that have been type approved as a tyre-stud combination must be affixed with a sticker in accordance with Annex 2 to the Regulation.

According to section 5.4. of Traficom Regulation TRAFICOM/383441/03.04.03.00/2022, tyres studded with type-approved studs may be affixed with a sticker, but this is not mandatory.

The stud image used in the sticker can be the kind of stud drawing as shown in Appendix 2.

Traficom Regulation TRAFICOM/383441/03.04.03.00/2022 does not provide an unambiguous answer to the question. Using a phase A marking or leaving the A marking out during the implementation phase are both acceptable practices. However, we strongly recommend not using phase A markings on the tyre stickers of tyre-stud combinations that have been type-approved before the entry into force of the Traficom Regulation.

The legal reference valid at the time of production of the tyre is used on the sticker.

The stud protrusion requirements for tyres are determined by the protrusion requirements valid at the time of type approval.

The protrusions of tyre studs in tyre-stud combinations type approved on or after 15 March 2024 must meet the requirements of Table 2 of Traficom Regulation TRAFICOM/383441/03.04.03.00/2022.

The stud protrusion requirements for tyres are determined by the protrusion requirements valid at the time of type approval.

The protrusions of tyres fitted with type-approved studs on or after 15 March 2024 must meet the requirements of section 5.1 of Traficom Regulation TRAFICOM/383441/03.04.03.00/2022.