The driver, 26-year-old Inthonkorn Janrasklang, said the bus’ brakes failed as he approached the Intersection near the Khok Kloi Bus Station at about 2pm.
Mr Inthonkorn said he swerved off the road to avoid ploughing into traffic waiting at the traffic lights.
Mr Inthonkorn explained to Takua Thung Police Inspector Lt Thavorn Thongkam that the bus was carrying 42 passengers from Khao Lak to Phuket.
Three passengers were taken to Takua Thung Hospital for treatment of injuries.
“The other 39 passengers are fine,” Lt Thavorn said.