"I have crossed this intersection several times and know very well how much traffic this main road uses," wrote the Duke of Edinburgh, blaming the incident with bright sunlight.
"The sun was shining low over the main road," wrote Philip. "Under normal circumstances, I would have no difficulty seeing traffic from the direction of Dersingham, but I can only imagine that I did not see the car and I am very dissatisfied with the consequences."
Fairweather told the mirror that she remembered the busy day, but said she was grateful for the apology. The letter was dated Jan. 21
The accident turned the Duke's car to one side, and one witness later told the Press Association that he helped pull a bloody Philip out of the vehicle.
Fairweather was a passenger in the other car, next to the 28-year-old driver who had injured his knee and nine-month-old baby, that was unhurt.
"I was a bit shaken after the accident, but I was very relieved that none of you were seriously injured," added Philip. "I have since learned that you have broken an arm, and I am very sorry about this injury."
"When a crowd began to gather, I was advised to return from a local police officer to Sandringham House," he adds.
After receiving the letter, she told the newspaper, "Me found it really nice that he signed as & # 39; Philip & # 39; and not as a formal title. I was pleasantly surprised because it was so personalized.
The incident dominated the British media and led to a public debate over whether people over a certain age need to repeat their driving tests.
The queen does not have this Philip holds a driver's license, and a royal source told CNN after the crash that the prince owns a license and complies with all the procedures required to keep it up to date with their helicopter Visited Britain in 2016 with the queen in the backseat.