Police said the accident happened on the outbound Serithai Road in Min Buri district at about 10 am.
The truck driver, Charas Chuakoodru, 46, waited for police after the accident. The woman was identified as Sunan Kachawiset.
Charas claimed that the woman, was waiting on the road island for his truck to pass but she suddenly stumbled on her own leg and fell onto the road in front of his truck. He said he could not stop his truck in time and it ran over her.
He claimed he was driving at the speed of only 40 to 50 kilometers per hour.