The Swiss woman was driving near Thayngen in the canton of Schaffhausen at around 3.30pm when her car crossed into the oncoming lane "for reasons unknown" and collided with a truck coming the other way, cantonal police said.
The car overturned, skidded on its roof and was hit by an oncoming car.
The accident wrote off all three vehicles and the road was closed for several hours due to the “complex salvage operation”, said police.
However all three drivers were able to walk away from the scene. Despite the extensive damage to her car, the 48-year-old only suffered “minor injuries,” said police.
She was nevertheless taken by ambulance to Schaffhausen cantonal hospital.