A drunken duo threw traffic cones on to the motorway after walking home on the M62, a court heard.
Callum Morley and Ashley Knowles, both 19, tossed cones into all three lanes of the eastbound carriageway at 3.45am last month near Junction 32 at Glass Houghton.
Wakefield and Pontefract Magistrates’ Court heard how the teenagers decided to walk home after running out of money during a night out on February 1.
Prosecutor Amanda Harris said they walked some distance on the motorway, picked up the lane dividers at “regular intervals” and threw them on to the carriageway.
A police car was sent to the scene and the duo were arrested.
Morley, of Orchard Lane, Tadcaster and Knowles, of Pinfold Avenue, Sherburn-in-Elmet, both admitted interfering with traffic equipment likely to cause danger and remaining on the motorway while on foot.
John Ratcliff, for Morley, said: “He was quite horrified to think what could have happened to other drivers as well as he and his friend.”
The solicitor told the judge: “You may think it occurred because he drank too much beer.”
John Wilkinson, for Knowles, said: “He clearly appreciates it was a stupid thing to do.”
Deputy District Judge Sandra Knapton, sentencing both to 150 hours of unpaid community work, said: “It’s beyond this court’s belief that anybody in their right mind would have behaved in the way you two did.”
“To walk on a motorway is bad enough, but to start throwing cones into the traffic lanes...Throwing traffic cones in all three lanes was completely and utterly ridiculous. You put yourselves at risk and other people as well.
“It’s solely because you had far too much to drink.”
Both must also each pay £85 costs and a £60 surcharge.