Korean program for enhancing driving stability of vehicles in high winds

The driving safety based on the risk index was evaluated from the lateral deviations of various vehicles under side wind computed by the dynamic motion simulation software. The critical wind speeds for the driving safety were respectively found as 35m/s for sedan and minivan, and 30m/s for bus and truck. The road-side wind screens were studied in the wind tunnel tests to protect the traffic accidents caused by high side wind. From the wind tunnel tests, the minimum height of a wind barrier required to reduce the wind speed by 50% was found to be 12.5% of the road width. It was also found that the speed reduction ratio on bridge did not decrease until the gap reached 30m if wind screens were equipped at both sides of the decks. All benefits drawn by installing wind screen and all costs caused by construction of wind screen were defined quantitatively. And then the decision making process for wind screen installation was proposed based on the benefit-cost ratio.