Road networks play a vital part in maintaining a functioning modern society. Many events perceptibly affect the transport supply along these networks, especially natural disasters such as floods, landslides, and earthquakes. Contrary to more common disruptions of traffic from accidents, or maintenance closures, natural disasters are capable of destroying large numbers of roads and usually cover vast areas. Six highly damaging natural disasters, which occurred in the Czech Republic between 1997 and 2010 will be presented. They were all induced by extreme rainfall or by rapid snowmelt and resulted in floods and landslides. Their impacts were evaluated with respect to the damage to road networks and decreased serviceability. For mutual comparison of the impacts several criteria related to economic impacts, physical harm to individuals and infrastructures, and the effects on connectivity and serviceability were used. Finally a detailed example from one such event in July 1997 that significantly affected the road network of the Zlín region will be outlined.