A youth threw a traffic cone from a footbridge onto a motorway in High Wycombe, a shocking viral video has revealed. 

The video - which has been viewed more than 218,000 times - was shared on Instagram page, The Street Blogs. 

It shows a young man throwing a traffic cone onto the motorway below after being encouraged by his friend who is filming. 

The location the video was filmed has not been confirmed, but it is believed to be in the High Wycombe area. 

The cone bounces onto the road below, narrowly missing fast-moving traffic. 

Viewers slammed the potentially deadly stunt, commenting that it was "stupid".