The van driver, Chaiwat Bamrungsin, 40, suffered only minor injures in the impact.
Capt Warawut Sensop of the Thalang Police was notified of an accident at 4:50am.
When rescue workers arrived, Mr Chaiwat was still trying to exit the van via the driver’s door.
He had suffered a concussion and was still experiencing chest pains, and was taken to Thalang Hospital before Capt Warawut and fellow police officers arrived.
While receiving first aid at the scene, Mr Chaiwat told rescue workers that he was heading home to Tambon Thepkrasattri, north of the monument, after finishing work in Samkong.
He swerved to avoid a truck and trailer coming through the roundabout, he said.
However, Capt Warawut told The Phuket News at the scene early this morning, “At this stage we believe that the driver was asleep at wheel and collided to the rail around at the monument as there were no skid marks on the road.
“However, we are continuing our investigation and will check CCTV footage.”
Mr Chaiwat will be charged with reckless driving causing damage, Capt Warawut confirmed.
“We will also also ask medical staff to check his blood-alcohol concentration,” he added.