As thousands of Athenian holidaymakers headed home yesterday after Christmas, careless driving and badly maintained roads caused a series of highway pile-ups, in the worst of which three people were killed and two injured. Six cars were involved in a crash just after 1 p.m. near Xylokastro, on the narrow highway from Patras to Corinth, in which Angeliki Bouziani, 55, Constantinos Lambropoulos, 15, and Dimitrios Sagonas, 59, died. Two hours later, a couple of simultaneous pile-ups within 400 meters of each other on the north-bound lane of the Athens to Corinth highway, near Aghioi Theodori, caused no serious injuries but led to severe traffic jams for up to an hour and a half until the 28 cars involved could be towed away. Corinth police blamed the accident on reckless driving. At the same time, on a highway just outside Tripolis, 15 cars were involved in a pile-up that police attributed to the poor state of the road.