DEVELOPMENT OF A SINGLE-VEHICLE CRASH SEVERITY MODEL INVOLVING COLLISIONS WITH ROAD SAFETY BARRIERS ON TOLL ROADS

• Main Author: Nabila, Syahla
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84584
• Institution: Institut Teknologi Bandung

Traffic crashes have become an increasingly significant problem in Indonesia, especially on toll roads. A common type of crash on toll roads is a single-vehicle crash caused by loss of control, which often results in a collision with a safety barrier. This study aims to identify the factors influencing the severity of safety barrier collisions by developing a severity model for these types of crashes. The severity model for safety barrier collisions was developed using a logit model, considering two types of logit models: the multinomial logit model and the nested logit model. The data used for this model development were sourced from the Cipularang toll road and two sections of the Trans Jawa toll road. The categories of accident severity were divided into Property Damage Only (PDO), slight injuries, and serious and fatal injuries. The suitability of the nested logit model was tested using the Hausman test, which showed no violation of the IIA assumption, leading to the final development of only the multinomial logit model. The modeling results indicate that the severity of safety barriers collisions is associated with average daily traffic, the involvement of heavy vehicles, the time of the accident, as well as the type and location of the safety barrier struck. The analysis results indicate that collisions with concrete roadside barriers result in the highest probability of fatalities and serious injuries compared to other type of safety barriers, while collisions with cable barriers result in the lowest probability of fatalities and serious injuries. Additionally, collisions between light vehicles and safety barriers of any type have a higher probability of fatalities and serious injuries compared to collisions in involving heavy vehicles. Moreover, collisions with safety barriers that occur during the day have a higher probability of fatalities and serious injuries compared to those that occur at night.