Report on serious traffic incident with a drawbar trailer on county road 715, at Storsteinan, Trondheim on 6 August 2018

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In the morning of Monday 6 August 2018, a heavy goods vehicle with two hooklift containers was driving along Bynesveien on the fv. 715 county road. In a gentle right-hand bend, the trailer drawbar broke at the weld during normal driving and without being exposed to other forces. The drawbar trailer broke free, entered the opposite lane and rolled over on its side. When it came to rest, the drawbar trailer completely blocked the road. No road users were injured as a result of the incident.

The drawbar trailer was approved by the NPRA, but the drawbar installed was not in accordance with the submitted documentation. The NPRA failed to uncover this in connection with the trailer’s approval. In the course of this investigation, the AIBN has considered how requirements for and testing of trailer drawbars are quality assured through the Norwegian Car Regulations as compared to what is described in the EU Framework Directive 2007/46/EC.

The AIBN initiated an investigation into the traffic incident because a break had occurred in a safety-critical component of a relatively new drawbar trailer. In this investigation, the AIBN has focused on the structure and modification of the trailer drawbar, design requirements and inspection in connection with its initial approval.

At the early stages of the investigation, the AIBN’s assessment was that the break occurred as a result of a modification of the drawbar before the initial approval of the trailer. The AIBN therefore issued a notification of a critical safety issue to the Norwegian Public Roads Administration (NPRA).

The AIBN is of the opinion that a safety barrier is missing in the conditions when it comes to competence- and quality terms of safety documentation with individual approval of trailers in the Norwegian Car Regulations.

The AIBN issues two safety recommendations as a result of this investigation.

Interim safety recommendation

13 September 2018 AIBN issued an interim safety recommendation in connection with this investigation.

Interim safety recommendation.

Safety recommendation

Safety recommendation ROAD No 2019/19T

The investigation into the traffic incident on the fv. 715 road on 6 August 2018 has shown that the trailer drawbar failed because it was undersized during production. The investigation has also shown that the Norwegian Public Roads Administration's internal procedures failed to identify this defect when the trailer was approved. More trailer drawbars used in Norway are manufactured in the same way.

The Accident Investigation Board Norway recommends that the Norwegian Public Roads Administration review and improve its internal procedures to ensure that sufficient attention is paid to safety in connection with individual approval and registration of trailers.

Safety recommendation ROAD No 2019/20T

The investigation into the traffic incident on the fv. 715 road on 6 August 2018 has shown that it was not discovered in connection with the trailer's approval that the trailer drawbar was undersized. The EU Framework Directive 2007/46/EC sets out a clear distinction between manufacturers and technical services, while Section 9 of the Norwegian Car Regulations allows manufacturers to document that their own products comply with the regulatory framework without setting any formal requirements concerning the manufacturer's competence. The investigation has shown that it is demanding for several parties to maintain a complete overview of the requirements that must be met and documented in order to register a trailer.

The Accident Investigation Board Norway recommends that the Norwegian Public Roads Administration, in cooperation with the industry, review and consider the need to amend the regulations that govern individual approval of trailers in Norway.

Fv. 715, Storsteinan, Trøndelag
Occurrence date
Accident type
Other accident
Road class
County road
Police Disctrict
Vehicle type
Truck and trailer
Type of Transportation
Freight transport
Road region
Central Region
Accident category
Ulykke m/ kjøretøy over 7500 kg
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