A lane of the motorway was blocked for most of the day in the Courgevaux area of the canton of Fribourg on Monday because of a landslide caused by the busy rodent, cantonal police said on Tuesday.
Several tonnes of earth and rock covered the roadway early in the morning and it took a crew with earth-moving equipment until the evening to clear it up, police said.
The beaver had blocked a stream running parallel to the motorway.
Pressure from the water burst a retaining wall, triggering the landslide, police said.
There was no information on what happened to the beaver.