Report on a head-on collision between av passenger car and a heavy good vehicle on the Rv 7 road in Flå on 21 May 2024
Road traffic report 2025/02
The head-on collision on 21 May 2024 on the Rv 7 road in the centre of Flå occurred when a passenger car crossed over into the opposite lane at a speed of approximately 60 km/h and collided with a heavy goods vehicle. A family of five were in the passenger car, a Tesla Model S 85D 2014 model, who were travelling south. The speed limit through the centre of Flå was 40 km/h. The driver of the passenger car did not notice that the road turned gently for a short time just before the collision. The HGV driver had seen the passenger car and slowed down before the collision. This reduced the forces of the collision considerably. Despite this, two of the people in the rear seat of the passenger car sustained critical injuries and the other people in the car sustained minor injuries. The NSIA’s investigation has revealed that the regulations for rear seat safety are insuffcient. Although the passenger car met the individual requirements for both seat belts and the strength of the rear seat, parts of the rear seatback collapsed in the collision. The regulations do not take into account how much a rear seatback should withstand in a collision when there is both cargo in the trunk and passengers in the back seat. The investigation also provides several learning points for road users about securing occupants and luggage in passenger cars.
The NSIA decided to initiate a safety investigation of the accident based on the major difference in the severity of the injuries sustained by the occupants of the passenger car. The investigation has mapped the sequence of events inside the passenger car, as well as the car’s construction and safety systems that had a bearing on the severity of the injuries in the accident.
Everyone in the car was wearing a seat belt. The car was properly packed, and no heavy items were loose or entered the vehicle body from the boot. The total weight in the boot was approximately 67 kg. The booster seats used by two of the children were suitable for the children’s age and size. The serious injuries sustained by an adult and one of the children of the rear seat can be explained by the incorrect use and adjustment of seat belts, combined with fewer supplemental restraint systems (airbag, seat belt pretensioner and force limiter), and the rear seat-back collapsing in the collision. Active seat belts and airbags helped to limit the injuries of the occupants of the front seats.
The NSIA finds that the passenger car passed the requirements set out in the regulations for both belt anchorage and rear seat strength. The requirements, however, do not show how rear seat strength, luggage and seat belts should work together. The NSIA believes that the dynamic forces in the accident were within what the vehicle's design should be able to withstand in terms of the mass of luggage and occupant weight.
The NSIA performed static tensile tests on a reference car to see how much load the rear seat-back could withstand when tensioned longitudinally, and whether it was possible to find out what caused the rear seat-back to collapse. The tests showed that with sufficient distortion, lateral forces occurred in the locking mechanism, which significantly reduced the strength of the connection in the rear seat-back. The rear seat-back collapsed at a load equivalent to around 1,000 kg in one of the tests. Based on this, the NSIA calculated that the rear seat-back could withstand less than 30 kg of pressing load when the rear seat-back simultaneously secured a light adult person, like the conditions in the accident.
Tensile test of rear seat-back and anchorage.
The NSIA believes that regulations must change to improve safety for rear seat passengers, but this is a process that requires international agreement. A first step towards changing the regulations may be to raise the issue in The European New Car Assessment Programme (Euro NCAP). Tesla should also take a closer look at the car model’s design for ensuring the safety of rear seat occupants. The NSIA moreover encourages car manufacturers to develop tests to ensure that their design solutions improve the safety of occupants of different sizes sitting in all positions.
The investigation also provides several learning points for road users about securing occupants and luggage in passenger cars. Also see the NSIA’s previously published information video on the correct adjustment of seat belts.
The NSIA submits one safety recommendation to the Norwegian Public Roads Administration and one safety recommendation to Tesla Norway as a result of this investigation.
The accident site. Photo: NPRA
Published 03.07.2025
Safety recommendation
Safety recommendation ROAD No 2025/08T
The head-on collision on 21 May 2024 between a heavy goods vehicle and a passenger car occurred when the passenger car crossed over into the opposite lane at a speed of approximately 60 km/h. There were five people in the passenger car, where two of those in the rear seat sustained critical injuries and the other occupants of the car sustained minor injuries.
The NSIA finds that the passenger car passed the requirements set out in the regulations for both belt anchorage and rear seat strength. The requirements, however, do not show how rear seat strength, luggage and seat belts should work together. In this accident, the rear seat-back was subjected to tensile forces from luggage and loading from an adult occupant fastened in the middle rear seat. This led to distortion of the rear seat-back, which in turn led to the striker in the wheel arch being torn off. The NSIA is of the opinion that the forces in the accident were within the level the vehicle should be designed to withstand in terms of luggage mass and occupant weight.
The Norwegian Safety Investigation Authority recommends that Tesla Norway investigate whether the safety of rear seat occupants in the car model (Tesla Model S) can be improved with regard to the design and anchorage of the rear seat-back and the securing of luggage in the boot.
Safety recommendation ROAD No 2025/09T
The head-on collision on 21 May 2024 between a heavy goods vehicle and a passenger car occurred when the passenger car crossed over into the opposite lane at a speed of approximately 60 km/h. There were five people in the passenger car, where two of those in the rear seat sustained critical injuries and the other occupants of the car sustained minor injuries.
The NSIA finds that the passenger car passed the requirements set out in the regulations for both belt anchorage and rear seat strength. The requirements, however, do not show how rear seat strength, luggage and seat belts should work together. In this accident, the rear seat-back was subjected to tensile forces from luggage and loading from an adult occupant fastened in the middle rear seat. This led to distortion of the rear seat-back, which in turn led to the striker in the wheel arch being torn off. The NSIA is of the opinion that the forces in the accident were within the level the vehicle should be designed to withstand in terms of luggage mass and occupant weight. A first step towards changing the regulations to better safeguard the safety of rear seat occupants may be to raise the issue in Euro NCAP.
The Norwegian Safety Investigation Authority recommends that the Norwegian Public Roads Administration propose to Euro NCAP to expand the safety assessment of passenger cars to include factors relevant to the safety of rear seat occupants. For example, whether locking mechanisms for split rear seat-backs and luggage securing systems, such as wire mesh or netting and hooks for straps are available.
Facts
| Location | Rv. 7, Flå, Buskerud |
| Occurrence date | 21.05.2024 |
| Accident type | Head-on collision |
| Road class | National road |
| County | Buskerud |
| Vehicle type | Passenger car, Truck and trailer |
| Type of Transportation | Freight transport, Private transport |