Evaluation of The Road Vulnerability Network During the Evacuation Process (A Case Study in A Coastal Area of Bengkulu City, Indonesia)

This study aims to determine the road network's performance for the Pantai Panjang and Bencoolen Mall areas in Bengkulu City, Indonesia, if a tsunami disaster occurs. The traffic on roads and questionnaire survey on respondents who occasionally come to the study areas is performed. The numerical analysis is conducted using four-step modelling based on various road condition scenarios to evaluate the road network performance. Scenario 1 considers existing conditions during tsunami evacuation; Scenario 2 considers increasing road capacity and adding two new road sections using traffic flow simulation during tsunami evacuation; Scenario 3 considers the addition of one new road section using traffic flow simulation during tsunami evacuation. For Scenarios 4, 5 and 6, the previous scenarios are evaluated by considering the increase in vehicle numbers in the next five years. Scenarios 1 and 4 show that there is an increase in the degree of saturation up to 0.68. It shows that the level of road service decreases. The road modification scenarios (Scenarios 2 and 3) show improved service levels. The modelling results with scenarios using traffic flow data under the improvement of road service for the next five years (Scenarios 5 and 6) show that the level of road service is better than the existing model. The road modifications scenario also effectively reduces the vulnerability index. The local government could also consider the results to improve the tsunami disaster mitigation in the study area