Method and arrangement for collision avoidance

Embodiments herein relate to an arrangement and a method for improving the performance of an automotive vehicle collision avoidance system. The presence of a target object (3) in front of a vehicle (4) hosting said arrangement (1) is established. The presence of one or more further obstacles (8) preventing the host vehicle (4) to safely steer past the target object (3) is established. The risk of a collision between the host vehicle (4) and the target object (3) is assessed, whereby an established presence of a target object (3) and one or more such further obstacles (8) are included in the risk assessment. Automatic emergency braking of the host vehicle (4) is initiated based on the risk assessment. Knowing that the possibility to steer around e.g. a forward vehicle may be blocked by a road barrier or another vehicle automatic emergency braking may be initiated earlier, whereby an improved speed reduction may be provided.