The accident took place on Thursday evening around 9.30pm at Champtocé-sur-Loire near the town of Angers.
According to reports the car crashed through the barrier on a bridge over the train line and plummeted on to the tracks below.
The driver may have survived the fall but seconds later a TGV train heading from Paris to Nantes, carrying 500 passengers ploughed into the car at 200km/h.
Passengers reported a “violent collision” and the train reportedly carried on travelling for a further two km with the wreckage of the car trapped underneath it, before it finally came to a halt.
The 26-year-old woman, who was driving the vehicle was killed instantly. Investigators are still unclear what had happened the moments before her car crashed through the barriers on the bridge.
The mayor of the local town questionedwhether she may have been driving too fast.
The bridge in question "is after a turn in an area where the speed limit is 70km/h. So at night, if you take this turn 110 or 120km/h then yes, it is dangerous,” the mayor said.
“We felt it had hit something metal,” said one passenger. “We felt it go under the train and it made a lot of noise. The driver braked very fast.”
French rail operator SNCF praised the driver for taking the necessary steps to prevent a possible disaster.
“The driver carried out all the correct safety measures to bring the train to a halt and stop other rail traffic on the line,” a spokeswoman said.
The passengers on the train escaped without injury. The TGV remained blocked on the track for two hours. Another train had to be despatched to pick up the passengers, who eventually arrived in Nantes five hours late.