Seada Mohammed Assen^1,, Emer Tucay Quezon²

In heterogeneous traffic conditions, the performance of the road network is described by vehicles and driver characteristics. Nowadays, traffic congestion, delay, and unreliability are terms that are most associated with present-day travel, in which transport users spend their precious time on long traffic queues. Due to this, late arrival at the workplace and appointment for social or business activities have become a perennial problem in the study area. In addition, during traffic queues, vehicle fuel emission increases in congested traffic segments affecting the environment, particularly the issue of global warming. This research study evaluated the performance of the road network in terms of travel time reliability in order to determine the main factors affecting travel time reliability. Ten road segments were selected to analyze the performance level and efficiency of the road network, considering the travel time probability distribution, and reliability of road segments in Addis Ababa City. From these road segments, nine were selected to formulate the model, and one road segment considered for validation of the result. The reliability of the road segments was analyzed using travel time reliability measures such as buffer time, buffer time index, planning time index, and the travel time index. It was used a multiple linear regression model to predict the travel time reliability of the road segments with R²_adj =0.936. In this research study, there were 1,141 samples considered for the analysis. A cross-validation analysis conducted on the models to estimate how accurately a predictive model will perform in practice. Hence, it is concluded that the regression analysis showed all variables found to have statistically significant to predict the travel time reliability of a road segment.

Buffer time index, Congestion, Regression analysis, Travel time index, Travel time reliability