South Koreans are celebrating Chusok, or harvest festival holiday. In the morning, families and relatives held a memorial service for their ancestors and visited their tombs in the afternoon. Roads leading to cemeteries across the nation were clogged all day with the vehicles of those visiting ancestors' tombs. During the three-day holiday which ends on Sunday, about 30 million travelers are expected to hit the road, creating major traffic congestion on the nation's highways and by-ways.