All Toronto-bound lanes of the QEW in Niagara Falls are blocked after a dump truck hit an overhead sign late Friday morning.
Ontario Provincial Police say the closure is at Mountain Road and is expected to last for three hours.
Photos posted by police on social media show the damage caused by the collision.
Police say the truck driver initially fled but has returned to the scene. No word on what charges will be laid.
This is the second incident involving a dump truck this week that has resulted in the closure of the highway.
On Tuesday, another dump truck struck a pedestrian overpass on the QEW in Mississauga, closing the highway in both directions for hours.