Report on the head-on collision on 27 May 2021 between two heavy goods vehicles on the RV 4 road just north of the Hagan tunnel near Slattum in Nittedal municipality

Photo: NSIA

Vehicle A was northbound through the Hagan tunnel and started to make a left turn approximately 200 metres before the northern tunnel portal, where the final CCTV camera inside the tunnel is located. On leaving the northern portal, Vehicle A had moved all the way into the opposite lane.

Vehicle A continued its leftward turning movement up until about two seconds before the collision, possibly following an even curve from the location of the final CCTV camera in the tunnel to the point of collision. The speed of Vehicle A through the Hagan tunnel up until the point of collision developed in accordance with the longitudinal slope of the tunnel, the weight of the heavy goods vehicle and an even, passive application of the brakes.

The investigation has shown that the drivers could have spotted the headlights of each other’s vehicles approximately five seconds before the collision, at the earliest, at which time they were on course to collide. The driver of Vehicle B did just about everything possible to prevent the collision and acted in line with what can be expected of a heavy goods vehicle driver in the given situation.

The investigation has shown that Vehicle A most probably entered the opposite lane because the driver fell asleep, at the same time as he kept the brake pedal and steering wheel in more or less stable positions up until the point of collision. Fatigue may have prevented the driver from becoming alerted when he crossed the centreline and rumble strip during the period before the accident.

Vehicle A’s tractor unit was a Slovenian registered Volvo (2015 model), and had only limited safety devices and no technical driver support system. As from 7 July 2024, it will be mandatory for all vehicles in EEA Member States to have a Driver Drowsiness and Attention Warning (DDAW) system.

The present and previous investigations have shown that it is possible to fall asleep behind the wheel even if the requirements for working, driving and rest hours are complied with, and that drowsiness while driving is a safety problem. In submitting this report, the NSIA urges government agencies, transport companies and truck drivers to be aware of this safety problem. Both transport companies and customers ordering transport of goods by road should actively seek to use vehicles that are equipped with a DDAW system.

Based on the investigation, the NSIA submits a safety recommendation for the tripartite transport industry programme.

Published 24.05.2022