Police from Wichit Police Station told The Phuket News that the victim was Jintana Mahattanapak, 43, the human resources director for the Hilton Phuket Arcadia Resort at Karon Beach, the largest tourist complex on the island.
The victim was driving a white Chevrolet car north on Chao Fa West Road around 8.30pm last night when she was killed by a single shot, fired through her side window from a car driving in the next lane.
Police think she died instantly, and her car continued at speed until it struck a lampost beside the road.
Crowds had already gathered when police from Wichit Police Station arrived at the scene, and the northbound lane of the road was blocked for several hours as the police searched for evidence from the shooting.
After reviewing recordings from CCTV cameras in the area, the police have refuted reports that the killers drove a black SUV: in fact, they were driving a white or "blond" coloured new-series Toyota Vios, although the license plate could not be identified.
Police say the CCTV camera recordings show Ms Jintana driving from the Chalong area towards Phuket Town - and that her killers were already in the car behind her when she stopped at a red light at the Thanon Kwang intersection and spoke to someone on her mobile phone.
When the lights changed, Ms Jintana started her car moving. The killers then drew alongside her car and fired the shot that killed her.
The police now think the shot was fired from the back seat of the Toyota Vios. After shooting Ms Jintana, the killers drove off at speed towards Phuket Town.
They have alerted all police stations in Phuket and the surrounding areas to watch for the vehicle and its occupants.
Ms Jintana's public profile on the LinkedIn social media website says she was the director of Human Resources at the Hilton Phuket Arcadia, and previously worked for other leading resort hotels on the island.