The N11 southbound in Co Wicklow has reopened following a collision in which a male cyclist was seriously injured this afternoon.
The man was hit by a truck on the dual carrigeway just outside Bray shortly after midday.
Gardai at the scene closed off the road close to the Powerscourt exit and long tailbacks developed almost immediately.
Traffic in the area is said to be still very heavy and motorists have been advised to find alternate routes where possible.
