This is the bizarre moment road barriers floating down the road past bemused drivers during a flash flood.

The highway was swamped with monsoon rains that washed away the plastic structures in Saraburi, central Thailand on July 21.

Passing driver Surasak saw the orange traffic barricades.

He said: ''I wandered what they were at first. They reminded me of a large caterpillar.''

Thailand and other countries in Southeast Asia are currently experiencing their annual rainy seasons, which sees torrential downpours from May until October.