This is the heartwarming moment a kind policeman fitted a temporary tail light onto the tricycle of an elderly scrap vendor on a busy truck route.

Police Sergeant Major Kritsana Singkha noticed the pensioner carrying recycled items on his tricycle as he struggled along Malaiman Road in Suphan Buri, Thailand.

The officer was concerned that he could be struck by cars and approached the man when he read a sign on the vehicle's back that read: 'A deaf person loves everyone.'

Footage shows the officer parking on the roadside and stepping out of his vehicle on November 17.

The senior citizen in a black helmet can be seen standing next to the three-wheeler. Kritsana then spoke loudly to the man and asked where he was heading.

Moments later, he installed his flashlight on the back of the cart as a makeshift tail light to prevent a possible accident.

When the man asked whether he needed to pay, Kritsana told him it was free, prompting the man to make a wai gesture of gratitude.

Kritsana said: 'I was afraid that the rider might be caught in an accident because many trucks travelled on the road and the night was approaching at that time. Truck drivers might not see him.'