The former Samut Songkram MP suffered a back injury in the accident, which occurred on a bridge over the Mae Klong River on the Samut Songkram-Pak Thor bypass road at about 2pm, police said.
When rescuers arrived at the scene, Rangsima was stuck behind the wheel by an airbag.
Doctors at Somdej Phra Phutthaloetla Hospital said the second joint of her spine had partially dissolved because of the crash impact. She received a strong painkiller.
Police said Rungsima’s car collided with a pick-up truck travelling in the opposite lane on the bridge.