The Effect of Heavy Vehicles on Road Performance R.E. Martadinata Palu Using a Model of the Relationship between Volume, Speed and Traffic Density

The traffic flow on a road segment is analyzed using three characteristics: Speed, Volume, and Traffic Density. Three models are employed to illustrate the mathematical link among volume, speed, and traffic density: Greenshield, Greenberg, and Underwood. This research aims to elucidate the correlation among volume, speed, and traffic density on the R.E. Martadinata Palu road section, evaluate the performance of the road segment, and examine the influence of heavy vehicles on the current conditions. The investigation of the three models, grounded in statistical evaluation and field features, culminated in the preliminary conclusion that the Greenberg relationship model yields the most accurate representation of the current conditions. The Greenberg model yields a coefficient of determination of r2 = 0.76 for scenarios involving heavy vehicles and r2 = 0.82 for scenarios devoid of heavy vehicles, with Vmaks values of 1725 smp/hour and 1534 smp/hour for each condition, respectively, and an estimated model capacity reduction of 11.07% when transitioning from conditions with heavy vehicles to those without. This signifies that the model's capability is affected by the traffic volume. Utilizing the MKJI 1997 methodology, the DS value was determined to be 0.56 with HV and 0.53 without HV, indicating that the RE. Martadinata road segment is much below saturation levels that would result in congestion during peak traffic periods.