Development of collision risk assessment model for bridge across waterways based on traffic probability distribution

Korea identifies in advance the impact of maritime development, including bridges across waterways, on maritime traffic safety and evaluates changes in maritime traffic flow and ship navigation safety by Maritime Traffic Safety Assessment. However, this system adopts the probability of collision per 10,000 vessels as a safety standard based on the number of collisions per vessel rather than the annual collision frequency during collision risk assessments through ship handling simulation, which is unsuitable for safety verification in sea areas with high traffic. Therefore, in this study, the annual frequency of collapse (AASHTO Method II) was used to convert collision frequency per ship into an annual collision frequency equation, maritime traffic distribution was analyzed for 4 bridges across waterways in Korea, and a normality test was performed. Through k-means clustering, passing ships were clustered by tonnage, and the annual collision frequency for each cluster was calculated. As a result, the annual collision frequency of once every 50–100 years was suitable depending on the ship size. This is similar to the annual collision frequency reported by International Maritime Organization, and it is judged to be suitable for use as an annual collision frequency safety standard not only in Korea but also worldwide. •Collision risk assessment safety standard for ship handling simulation is proposed.•Safety standard is derived using formula of AASHTO Method II.•The model is reviewed for ships passing under cable-stayed bridges in Korea.•The annual collision frequency was similar compared to the actual accident frequency.