The General Assembly of the United Nations, on December 11, 1987, designated the 1990s as the International Decade for natural Disaster Reduction (IDNDR). During this ten-year period, 1990 through 1999, special efforts should be made for reducing catastrophic loss of life, property damage, and social and economic disruption due to natural disasters, such as landslides, earthquakes and floods, throughout the world. In response to the UN appeal on IDNDR, PIARC organized a Working Group on « natural Disaster Reduction », which began its activities in 1990. The Group conducted various studies, including an international survey on road disasters.

This report first describes the results of the international survey of 21 countries. From the survey it is evident that landslides, earthquakes, floods, and snow avalanches are four major hazards causing frequent road-related disasters, and the other hazards include volcanic eruptions, tsunamis, storm surges, strong winds, and wildfires. Next this report deals with pre-event measures, including damage risk assessment and strengthening or retrofit, for landslides, earthquakes, floods, and snow avalanches. It also discusses repair methods for damaged road structures; post-event measures, including policy and organization for repair; and traffic management in emergency situations. Finally, it presents a summary, conclusions and recommendations for road management.