There are concerns teenagers are playing 'chicken' on the M50 .
A driver told the Irish Mirror that he was horrified after he captured the footage on his dash cam.
In the video, five boys can be seen leaning into the outside lane of the M50 while trying to find a gap in the traffic flow to race across three lanes.
Mark Clinch told the paper: "I didn't notice them at first. I just wondered why the car in front of me was braking so harshly.
"The last thing you expect to see on a motorway is a group of lads trying to cross so it was just unexpected. It scared the life out of me.
"They were leaning into the road so I genuinely thought they were going to run out in front of me and there wasn't enough room for me to stop.
"They ran out behind me and stopped in the lane for a gap. The car behind me swerved and I think they were a bit shook up."