Llandudno teenager Aaron Hall threw wood on to A55
A teenager who forced traffic to swerve when he hurled pieces of wood on to the A55 dual carriageway, has been sentenced to 12 weeks in custody.
Aaron Hall, 18, from Llandudno, Conwy, admitted causing danger to road users and criminal damage to a fence after the incident on a 50mph (80km/h) stretch at Colwyn Bay in February.
Llandudno court heard there was a "grave risk of danger" to motorists.
District Judge Andrew Shaw said it was "luck" nobody was seriously hurt.
He said: "It's a matter of simple good luck and good fortune nobody was seriously injured or killed."
The court heard Hall was with two other teenagers at the time.