Martha Becker, 73, noticed that the coach taking her and 28 fellow pensioners on holiday to Austria, was drifting towards the edge of the road – after the barrier there was nothing but a six-metre drop.
She called out to the driver but got no response and realised the 47-year-old had collapsed in her seat, Becker told Wednesday's Bild newspaper. The coach was travelling at about 60 kmph at the time on the motorway near Kitzingen, Bavaria.
It was already scraping along the crash barrier when Becker sprang into action and grabbed the wheel. She pushed her legs underneath the motionless driver, reaching the pedals and then carefully slowing the coach down before bringing it to a halt.
“If I had rammed my foot on the brakes we would have all gone through the front window,” the grandmother of three told the paper.
“She had a frozen stare and her face was snow-white,” she said of the driver.
Although Becker had run the company which owned the bus for the past 40 years, she had never driven one before.
The driver was taken to hospital for observation, but the reason for her collapse remained a mystery on Wednesday.
For Becker, the realisation of what happened only hit her afterwards. “It was only later that the feelings came through. I was shaking and had a headache,” she said.
“But I didn't want to have to abandon the holiday, so I was pleased.” A replacement bus took the group, from Rhineland-Palatinate, to their week-long holiday in Austria.
“Mrs Becker could have done no more for us than what she did,” said fellow passenger Achim Mockenhaupt.