A Singaporean woman injured during a road trip in Western Australia has regained consciousness, after being in a coma for nearly a week.

Ms Heidi Ang, 24, who was travelling with two friends, was behind the wheel when another car allegedly crashed into her rented Toyota Corolla hatchback last Friday. The trio were in the Margaret River region as part of a graduation trip.

The accident left Ms Ang, an account engineer, with three broken ribs and a traumatic brain injury.

Ms Huang Huifang, 24, a travel consultant, suffered bruises and cuts, while undergraduate Lim Zi Jie, 26, was unharmed.

Ms Ang was taken to the Royal Perth Hospital in a helicopter and put into a medically induced coma to address swelling in her brain.

Her brother, research analyst Wilmer Ang, 27, told The Straits Times yesterday that his sister has come out of the coma.

"She's slowly regaining consciousness and responding to our parents and the doctors, so that's a great improvement," he said.

"We were told that hopefully by next week, she will be in a condition to fly back to Singapore," he said, adding that they plan to admit her to Tan Tock Seng Hospital.

Mr Ang believes it was his sister's first time driving overseas.

He said: "Obviously, after this, we will discourage her from driving overseas. She probably wouldn't want to do it too."

Ms Huang, who is back in Singapore, told The Straits Times yesterday the accident had happened so quickly that "there was no time to respond or even to avoid it".

"The right side of our car was totally ruined, and the front and back doors were badly dented due to the impact," said Ms Huang, who was in the back of the car. "The airbags were deployed and the windows (of the car) were shattered."

Firefighters had to remove three car doors and the roof of the car to extricate Ms Ang, she said.

"We had talked about the possibility of future road trips to other parts of Australia and even to the United States. But I guess we would have to think twice about it."