Abstract: An improved deployment method for a vehicular supplemental restraint system, wherein the existence of a rough road condition is indicated if a measure of crash severity obtained from an acceleration sensor exceeds a rough road threshold and the crash event reset criteria are subsequently met with no intervening deployment of the restraint device. The rough road indication is maintained for a timed period, and normal deployment of the restraint device is inhibited during the timed period unless the acceleration signal exceeds a minimum threshold and the measure of crash severity exceeds an additional deployment threshold which is initially higher than the normal deployment threshold. When the rough road condition is detected, a counter is initialized to a predefined value, and then periodically indexed so long as no potential crash event is in progress. If the counter is indexed to another predefined value prior to another rough road detection, the rough road condition is reset.