From Ballyowen shopping centre drive through estates towards Hayden's lane then drive down towards Newcastle on the Adamstown/Newcastle road turning left at Pollyhops onto the new Nangor road, go straight through all roundabouts until you get to big junction with lights and turn right at lights. Follow signs for N7 south - from there to Naas it should take about 15 mins, all the traffic is around Superquinn and Pollyhops, both can be unpredictable in the Winter, fine in Summer.
Journey time in the summer to Naas 40 mins
Winter journey time min. 1 hour (all taffic on Adamstown road). To avoid Adamstown road go towards celbridge, turn left for Hazelhatch train station and out the back of Newcastle (from Lucan village this way is better but not sure it would be worth it from Ballyown SC).