Vulnerability assessment for the hazards of crosswinds when vehicles cross a bridge deck

• An assessment procedure is proposed for vehicle safety when encountering crosswinds while crossing a bridge deck.
• Long-term wind velocity and direction data for a given bridge site are utilized in the assessment.
• The effects of vehicle type and speed and loading lanes are investigated.
• The effects of bridge layout and deck shape are implemented in the assessment.
• Wind profiles for each of the traffic lanes are assessed via section-model wind tunnel tests.

A new procedure to assess the crosswind hazard of operating a vehicle over a bridge deck has been developed using a probabilistic approach that utilizes long-term wind data at bridge sites as well as the aerodynamic properties of bridge decks and vehicles. The proposed procedure for safety assessment considers the probabilities of two accident types: sideslip and overturning. The vulnerability of vehicles to crosswinds is represented by the number of days for traffic control that would be required to secure vehicle safety over a period of one year. The distribution of wind speed over a bridge deck was estimated from a section model wind tunnel test. A sea-crossing bridge was selected as an example, and a series of case studies were performed to identify the influential factors affecting vehicle vulnerability to crosswinds: vehicle type and loaded weight, the position of a running vehicle over a bridge deck, the bridge alignment relative to the dominant wind direction, and vehicle speed.