Report on a collision on E18 in Asker in Akershus county on 13 May 2019
Road traffic report 2020/05
On 13 May 2019, a heavy goods vehicle broke down while heading west in the middle lane on the E18 road near Asker. Approximately 20 minutes later, a passenger car ran into the rear end of the trailer. Both occupants in the passenger car died from the injuries sustained in the collision. The heavy goods vehicle broke down as a result of a rupture in the flexible brake hoses between the tractor and trailer. The investigation has shown that the hose was designed to carry oil, that it had been spliced in several places, and that it was not approved for the compressed air system. The trailer was approved in a roadworthiness test conducted approximately two weeks before the vehicle broke down. Inspection of hoses to verify that they are of an approved type was not a checkpoint, nor is it assessed whether any joints fail to comply with the manufacturer’s instructions. The Norwegian Safety Investigation Authority (NSIA) is of the opinion that the auto repair industry and owners of heavy vehicles should give more attention to regular inspections and maintenance of hose couplings in the brake system between the tractor and trailer. The annual periodic roadworthiness test also has a potential for improvement, and three safety recommendations are issued in this area. The investigation has also shown that limited access to variable signs in the area meant that road users were not made aware of the broken-down heavy goods vehicle. The NSIA is of the opinion that the Norwegian Public Roads Administration should consider increasing its use of surveillance cameras and traffic information to reduce the risk of accidents in connection with vehicle breakdowns and other unforeseen incidents on busy roads. One safety recommendation is issued in this area.
While driving on the E18 west, a technical failure occurred on a hose that supplies the trailer's braking system with compressed air. This resulted in the trailer's automatic braking system engaging with maximum braking force, and it was therefore not possible for the driver to continue driving. The breakdown occurred on a stretch with three lanes, in the middle lane driving west and at a time of relatively high traffic volume. The right lane was an entrance lane.
The investigation has emphasized the underlying conditions that led to the automatic braking system on the trailer engaging while driving and road user information on the stretch.
Findings showed that the breakdown occurred due to a hose rupture in the flexible brake hoses between tractor and trailer, and that the compressed air connections in this area can be vulnerable to external stresses during normal operation. The hose, which was part of the trailer's braking system, was according to the supplier designed for transporting oil and was spliced in several places. There were internal cracks next to the continuous rupture. The oil hose in question also had other properties and was less flexible than approved hoses intended for compressed air. The trailer was recently approved after a periodic roadworthiness test (PKK) without this being revealed, and the NSIA believes that there are areas for improvement for PKK in this area.
The NSIA is of the opinion that the combination of heavy traffic at high speeds, as well as the location of the heavy goods vehicle over time, posed a significant accident risk because the requirement for attention on this road was significantly tightened. The investigation has shown that limited access to variable signs in the area meant that road users were not made aware of the broken-down heavy goods vehicle. The NSIA is of the opinion that the Norwegian Public Roads Administration should consider increasing its use of surveillance cameras and traffic information to reduce the risk of accidents in connection with vehicle breakdowns and other unforeseen incidents on busy roads.
Published 27.08.2020
Safety recommendation
Safety recommendation ROAD No 2020/06T
On 13 May 2019, a heavy goods vehicle suffered a breakdown while heading west in the middle lane on the E18 road near Asker due to a hose rupture in the brake system between the tractor and trailer. Approximately 20 minutes later, a fatal accident occurred when a passenger car ran into the trailer. The investigation has shown that the compressed air couplings between the tractor and trailer can be vulnerable to external loads during normal operation. The compressed air hose between the tractor and the trailer was designed to carry oil. It had interior fractures in addition to the rupture. Oil hoses have different properties from and are less flexible than compressed air hoses, which should have been used.
The Norwegian Safety Investigation Authority recommends that the auto repair industry, represented by the Norwegian Motor Trade Association (NBF), inform its members of the importance of maintenance and the quality of hose couplings in the brake system between tractor units and trailers.
Safety recommendation ROAD No 2020/07T
On 13 May 2019, a heavy goods vehicle suffered a breakdown while heading west in the middle lane on the E18 road near Asker due to a hose rupture in the brake system between the tractor and trailer. Approximately 20 minutes later, a fatal accident occurred when a passenger car ran into the trailer. The investigation has shown that the compressed air couplings between the tractor and trailer are vulnerable to external loads during normal operation. The compressed air hose between the tractor and the trailer was designed to carry oil, and it had interior fractures in addition to the rupture. Oil hoses have different properties from and are less flexible than compressed air hoses, which should have been used. The investigation also found that the repair work had been performed by non-approved auto repair shops.
The Norwegian Safety Investigation Authority recommends that the Norwegian Truck Owners Association (NLF) inform its members of the importance of inspection and maintenance of hose couplings in the brake system between tractor units and trailers.
Safety recommendation ROAD No 2020/08T
On 13 May 2019, a heavy goods vehicle suffered a breakdown while heading west in the middle lane on the E18 road near Asker due to a hose rupture in the brake system between the tractor and trailer. Approximately 20 minutes later, a fatal accident occurred when a passenger car ran into the trailer. The trailer was approved in a roadworthiness test conducted approximately two weeks before the vehicle broke down. Inspection of hoses to verify that they were of an approved type was not a checkpoint, however; nor is there any assessment of whether any joints fail to comply with the manufacturer’s instructions. The NSIA is of the opinion that tractor-trailer couplings are vulnerable to external loads and that they must therefore be considered safety-critical components in brake systems.
The Norwegian Safety Investigation Authority recommends that the Norwegian Public Roads Administration improve the inspection of hoses couplings in the brake system between tractor units and trailers in periodic roadworthiness tests.
Safety recommendation ROAD No 2020/09T
On 13 May 2019, a heavy goods vehicle broke down while heading west in the middle lane on the E18 road near Asker. Approximately 20 minutes later, a fatal accident occurred when a passenger car ran into the trailer. The NSIA considers that the combination of heavy traffic, high speed and the position of the heavy goods vehicle over time posed a considerable accident risk because it required significantly greater attention on this section of road. The investigation has shown that limited access to variable signs in the area meant that road users were not made aware of the broken-down heavy goods vehicle.
The Norwegian Safety Investigation Authority recommends that the Norwegian Public Roads Administration review technical equipment with a view to improving traffic monitoring and traffic information on sections of road with high traffic density and high speed.
Facts
| Location | E18 Asker, Akershus county |
| Occurrence date | 13.05.2019 |
| Accident type | Collision |
| Road class | European road |
| County | Akershus |
| Police Disctrict | Asker og Bærum |
| Vehicle type | Passenger car, Truck and trailer |
| Type of Transportation | Freight transport, Private transport |
| Road region | Eastern Region |
| Accident category | Ulykke m/ kjøretøy over 7500 kg |