The present invention is directed to a quick release coupling, a displacement sensor, and an electronic monitoring unit. The displacement sensor is mounted near the end of the guardrail for measuring the force of a vehicle impact. The electronic monitoring unit is connected to the sensor and measures the acceleration of the impact and provides an actuation signal when the acceleration exceeds a predetermined value. The quick release coupling forms a connection between two separated portions of the guard rail and includes an explosively actuated release mechanism actuated by the monitoring unit.
David J. Stevens; Kirk A. Marchand; Joseph B. Mayer, Jr.