The force of the impact shunted the van forward, injuring two passengers and shoving the driver, Mana Thaweesapchusri, over the guardrail and plunging into the water about 20 metres below.
Mr Mana told police at the scene that he had parked on the bridge just before 7:30am.
“I was driving 10 passengers to make merit in other provinces for Asarnha Bucha Day,” Mr Mana said, before being taken to hospital.
“I stopped the van on the bridge for passengers to take photos. While they were standing in front of the van, a car hit at the back of the van.
“I fell down from the bridge about 20 meters into the water below. Luckily, a longtail boat was nearby to help me out of the water.” he added.
Mr Mana and one of his passengers, Supamas Kamphiranon, 62, were taken to Thalang Hospital for treatment of minor injuries
Another passenger, Dararat Nanthakitwiboon, 63, was taken to Takua Thung Hospital on the Phang Nga side of the bridge.
“People are not allowed to park on the bridge. It is very dangerous, but people still break the law and now this accident has happened,” said Capt Terdsak Keawmanee, Deputy Chief Inspector of the Khok Kloy Police.
Capt Terdsak confirmed that he would question the driver of the BMW sedan, which is registered in Phang Nga Province, about the accident.
However, the name of the BMW driver was not disclosed.