The Symposium on Effective Highway Accident Countermeasures was held in Washington, D.C., on June 12-14, 1990. The Symposium was hosted by the Federal Highway Administration in cooperation with the National Highway Traffic Safety Administration. The Symposium's objectives were to identify the most effective and practical short-term (within 2 years) countermeasures to highway accidents and to develop strategies for their implementation. The Symposium focused on five areas of highway safety: improving pedestrian safety, reducing accident severity, improving driver performance and control, improving commercial motor vehicle safety, and identifying and improving highway corridors. This publication summarizes the presentations and workshop reports.