Abstract
Methods of determining the likely speeds and frequency of occurrence of winds blowing across a bridge structure in any given location are described with the effects of such winds on high sided vehicles using the bridge. The critical wind speed above which a vehicle may overturn is derived in relation to its forward speed, weight, dimensions and the angle of yaw. The shielding effects of vehicular parapets are considered together with their capability of preventing an overturning vehicles from toppling off the bridge. Procedures adopted to assess the effects of wind speeds at various bridge sites in the British Isles are then given together with subsequent measures taken to control vehicle speeds or divert to other route. (A)