Lt Chanat Hongsittichaikul of the Chalong Police was informed of the accident, on Chao Fa West Rd, at the intersection with Soi Thanuthep and Soi Yodsanae, at 11am.
At the scene police and rescue workers found German national Thorsten Manuel Rudolf Rabl, 43, from Altotting, on the ground suffering from a serious head injury.
Chalong Municipality rescue workers administered first aid to Mr Rabl and sped to him Dibuk Hospital, Lt Chanat said.
His female passenger on the motorbike, who police named as Helga Rabl, 37, suffered only minor injuries in the collision.
Lt Chanat said he was yet to confirm whether the couple were husband and wife, or any other relation.
Both Mr Rabl and Ms Rabl were wearing helmets at the the time of the accident, Lt Chanat confirmed.
“According to CCTV, we can clearly see Mr Rabl crossing through the intersection as the lights were changing,” Lt Chanat explained.
“However, a white Honda Brio being driven by a Ms Ravit Goldstein, 46, passed through the intersection while the lights were changing from amber to red,” he said.
“The German man was crossing through the intersection to enter into Soi Yodsanae when the car came through. The motorbike hit the right side of the car hard and the couple on the motorbike fell onto the ground,” he added.
Ms Goldstein holds a valid Thai driver’s license, Lt Chanat confirmed, adding that Ms Goldstein is an American citizen.
However, Lt Chanat said he had yet to confirm what form of driver’s licence Mr Rabl had.
“At this stage we have pressed preliminary charges of reckless driving while we continue our investigation,” Lt Chanat said.