CALIBRATION OF HIGHWAY DEVELOPMENT AND MANAGEMENT-4 FOR ROAD USER EFFECT IN ETHIOPIA

The Highway Development and Management System (HDM-4) is software it sponsored by the World Bank and The model is a further improvement of its predecessors, HDM-II and HDM-III, which were respectively the second and third versions of the Highway Design and Maintenance Standards Series and its first version of the series known as the Highway Cost Model (HCM). This research focused on a level one and two calibration of Road User Effect sub model of High way Development and management HDM-4, specifically the fuel consumptions of small cars, Four Wheel Drive specially Pick up and minibus to the condition in Ethiopia. Also check the validation of the result compare to the predicted software value.
To meet the objective of the study, identify prior calibrations of road user effect parameter based on sensitivity. Methodology for interview and field data collection was crafted. Structured interview type used for interview and field data collection includes measurements of idle fuel consumption and fuel consumption travelling at different speed to get Base engine efficiency and Efficiency at higher power. The procedure of calibration is based on the provisions of the HDM-4 calibration manual prepared by Bennett and Paterson in the year 2000.
The result showed that the calibration factors are well within the typical values of factors included in the calibration manual of HDM-4 indicating that the road user effect models are generally applicable to Asphalt Concrete road to the Ethiopian condition. Then, according to HDM-4 calibration techniques, the result showed that the idle fuel consumptions adjustment factors become 1.32, 1.17 and 0.97.Also the efficiencies adjustment factors value which means base efficiency 0.45, 0.53 and 0.55 and efficiency at higher power 0.52, 0.9 and 0.612 for small cars, 4WD and minibus respectively.