EFFECT OF ROAD ROUGHNESS ON THE FREE FLOW SPEED OF MOTOR VEHICLE

• Main Author: Arifin, Syahrul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2904
• Institution: Institut Teknologi Bandung

EFFECT OF ROAD ROUGHNESS ON THE FREE FLOW SPEED OF MOTOR VEHICLE,Syahrul Arifin, 1997, Program Sistem dan Teknik Jalan Raya , Program PascaSarjana, Institut Teknologi Bandung The free flow speed dependes on such factors as carriageway and shoulder width, terrain type, side friction, road roughness, road class and land use. This thesis describes a study of the effect of road roughness on free flow speed of motor vehicles. The objectives of the study were to develop a model of the relationship between road roughness and free flow speed and also to study the effect of road roughness on free flow speed for each vehicle type. Data was collected from road segments, which had the following characteristies: • Two lane, two way undivided interurban road. • Flat and straight terrain. • Low side friction. • Road width approx 7 meter with unpaved shoulder width 1.5 - 3 meter. The sites chosen were on the Pamanukan - Lohbener link at sta 76+ 000 - 77+ 000, sta 83+ 000 - 84+ 000, 97 +000 - 98+ 000. Data were obtained from short base measurements in daylight. Total vehicles recorded were 1808 at site 1, 1896 at site 2, and 1514 at site 3. The road roughness value used was the NAASRA measurement. Free flow speed was used as the dependent variable in the analysis (linear regression). The results of the analysis indicate the significant effect of road roughness on free flow speed of motor vehicles, also its impact is different for each vehicle type. The road roughness - free flow speed relationships indicate that the effect of road roughness on light vehicles is greater than for heavy vehicles, under the same conditions. The slop of the relationship determined for large trucks , truck combinations is flatter that for light vehicles, medium heavy vehicles and large buses. The slope for light vehicles is -3.2984, for medium heavy vehicle -3.1926, and for large buses -2.9986, for truck combinations the slope is -1.9295, and for large trucks -1.7318