This is a terrifying moment a piece of wood flies through the air on a motorway before smashing a car window.

Tan Sirithienthong and her sister were driving on the highway when the the 5ft long post suddenly flicked up into the air.

It is believed to have been lying on the road before a passing truck hit it, with the pressure causing it to fly skyward.

Dash cam footage from Monday (19/08) morning shows the car was keeping on the right lane before the thick piece of wood came spinning towards it and smashed the driver's side window.

The driver is heard in the video saying ''shi-aah'' as the piece of timber hits the vehicle. She then pulled over and checked for damage.

Nobody was injured from the incident but the driver's window was shattered and the wing mirror was broken while the windscreen had several cracks.

Skaken Tan said: "I was totally shocked when we were hit by the wood. Luckily, I managed to keep on driving otherwise we could've been hit by the following cars if I stopped the car quickly.

"Many parts of the car were ruined but I was glad that my sister and I were not injured."

Meanwhile, the driver is contacting highway officials for the CCTV footage to find out exactly how the accident happened.