This is the shocking moment a motorcycle rider swerves across the road and smashes into a barrier.

The teenager appeared to lose control or take his eyes off the road while he was speeding along the highway in Samut Sakhon, Thailand, last Sunday (April 5) afternoon.

Car passenger Nawin Intarasuwan, who was travelling behind the youngster, started recording when he noticed him riding erratically at high speed without a helmet.

Shortly after, he lost his balance and swerved in front of Nawin's car and smashed into the traffic blockade.

The teenager had several wounds and bled seriously but was able to sit up at the roadside and talk with passersby who came to help him.

Nawin, who is heard screaming in the video, said: "Motorcycle riders should have more awareness while on the road. This accident should serve as an example for everyone to take more care.

''Drivers also have to look out for motorcycle riders that are being reckless and avoid crashing into them.''