The influence of freight transportation on road network performance in Surakarta

Abstract

One of the serious transportation issues is congestion since it can cause derivative problems in human’s life, such as pollution and economic losses. Congestion occurs when the road capacity is less capable to handle the traffic volume. Surakarta City is surrounded by Boyolali Regency, Sukoharjo Regency, and Karanganyar Regency. It makes a lot of freight transportation from outside of Surakarta city, which ultimately increases the traffic volume. The objective of this research was to estimate the origin-destination (OD) matrix, and to find out the road network performance in Surakarta City due to freight transportation as represented by traffic volume per capacity (V/C). Gravity model was used for estimating the O-D matrix. The value of parameter β as a function of deterrence function was found out by using maximum entropy method. The parameter β obtained was 0.081067. Subsequently, validity test was done using the coefficient of determination (R2) which represented the comparison of traffic flow from observation (traffic count) and from model was 0.831631. The process of trip assignment utilized EMME/3 software. The result showed the values of V/C in 2017, in which approximately 90.54% of roads in Surakarta City are in stable while 9.46% are in unstable condition (V/C>0.8). However, the absence of freight transportation will maintain 100% roads in the stable condition.