Impact of Overloading Vehicle towards the Level of Service on Freeway Segment (Case Study: JORR KM 27 to KM 23)

The congestion problem that occurs on the road is one of the indicators to determine the level of service. Approximately 20% of all traffic congestion is due to the existence of shockwave jams or phantom jams. One of the factors causing the shock wave phenomenon is the speed differences between heavy vehicles and light vehicles (Garber & Hoel, 2009). On the other hand, the Over Dimension and Over Loading (ODOL) Vehicle worsened the situation by reducing operational speed due to the exceeding load. Indonesia Traffic Police stated that throughout 2019 there were 136.470 vehicles out of 1.376.956 offences that were ODOL vehicles. This research aims to identify the effect of overloading vehicles and the volume of heavy vehicles on creating shock wave phenomenon that led to the lower level of service. Microsimulation modelling is carried out to obtain the resulting level of service from heavy vehicles volume using the primary data from the data collection. The result shows that the large volume of heavy vehicles exacerbated by the presence of ODOL vehicles can cause a temporary change in road speed and lead to a decreased level of service.