The tragic accident happened on a Sunday morning two years ago as a baker was delivering rolls in the canton of Thurgau.
As she was driving along the cantonal road at 6am she failed to spot the young man who had fallen asleep on the carriageway following a party.
The 26-year-old victim, who was drunk, had been on the way to the house of his grandmother when the accident happened.
The driver, travelling at 60 km/hr, failed to spot the young polymechanic in time and ran him over, killing him instantly.
Although she argued she had just been in the wrong place at the wrong time, local prosecutors opened a criminal investigation against the driver for negligent homicide.
On Thursday the district court in Frauenfeld acquitted the driver after the judge said she didn't believe the accident could have been avoided.
Earlier the judge had taken part in an unusual experiment, where the accident was created under the same conditions and at the same spot in the road using a crash test dummy.
The judgment comes just three months after another similar case came to court.
In June a court in Biel-Seeland convicted a driver of negligent homicide after he ran over and killed a woman who had lain down on a motorway with the intention of committing suicide.
The court ruled that he was driving too fast to be able to see an obstacle in the road in time to brake.
The driver was travelling at about 100km/hr – within the Swiss motorway speed limit of 120km/hr.