Tailbacks extend 14 kilometres back to Kildare Town.
A three car collision has created long delays along on the M7 and M9 motorways.
The incident, which happened between Naas and Newbridge led to a 14 kilometre tailback, which stretched to Kildare Town.
Normal traffic levels were already elevated, as hundreds of Clare and Kilkenny fans travelled to Croke Park for an All Ireland Senior Hurling Semi Final.
Gardai say the collision led to a lot of damage, which had to be cleared before lanes could be reopened.