Lt Col Suchat Meelumphong of the Phuket City was called to the scene of the accident on the northbound lane of the bypass road at 5am.
At the scene, police and Kusoldharm rescue workers found a black Phuket-registered Toyota Vios on its side.
The driver of the car, not named in the initial accident reports, suffered only minor injuries.
Her passenger, Netchanok Detaran, 42, was lying on the road near the car. She was conscious and responsive, but had suffered serious head injuries.
Ms Netchanok was rushed to Bangkok Hospital Siriroj (formerly the Phuket International Hospital), but was later pronounced dead.
The driver of the car told police that she fell asleep at the wheel, leading to the accident.
Police have yet to reveal any further details about the accident.
At 5:20am, Capt Kraisorn Boonprasop of the Thalang Police was called to the scene of another serious accident, on Srisoonthorn Rd near the Supalai Essence Phuket residential estate, in Moo 5, Srisoonthorn.
Police together with Kusoldharm rescue workers arrived at that scene to find white Phuket-registered Toyota Vios with heavy damage to its front.
The driver, Warinrada Sukkaew, 29, originally from Surat Thani, suffered a minor injury to her left leg, and her passenger, Phuket native Supawadee Songsri, 26, suffered a bloody nose from the air bag deployed in the impact.
Both were taken to Thalang Hospital.
Ms Rinrada told police that she and Ms Supawadee were going home after a birthday party.
Ms Rinrada said she lost control of the car on the curve at the scene, and was unable to avoid crashing into the power pole.
The accident left houses and businesses in the immediate area without power supply.
Police have yet to release further details about the accident, and whether Ms Rinrada was tested for alcohol.
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