THE EFFECT OF SIDE FRICTION ON DELAYS IN ONE-WAY URBAN ROAD SECTIONS

Abstract

The effect of side friction activities on delays due to the reduced free-flow speed was investigated by conducting a series of traffic surveys and referring to the 1997 Indonesian Highway Capacity Manual (IHCM) parameters. The movement of pedestrians, parking/stopping vehicles, vehicles entering and exiting the road, and the slow-and-stop motion of vehicles on the road sections was observed in video footage and analyzed to estimate the effect of side friction on the delays occurring. A weighting factor was used to determine the total value of side friction on the road to test the combined effect of all activities. This study used a regression model for estimating vehicle delays, as a performance parameter, on urban road sections, taking into account the effect of side friction on the road section's vehicle free-flow speed (FFS). It was found that vehicle speed decreased when side friction increased at all levels of traffic volume. Low side friction produced a higher vehicle free-flow speed (FFS), and analysis of the free-flow speed (FV) showed a lower vehicle free-flow speed (FFS) than that in the 1997 IHCM analysis. Delays at undersaturated inseparable one-way road sections (2/1 UD) with low to high side friction were described by the equation: Y = 0.002 X + 0.028 (R2 = 0.704) for Panca Usaha Road, and Y = 0.0022 X + 0.0104 (R2 = 0.774) for Pejanggik Road, where Y = Delay, X = Traffic Flow. The results of the above study indicate the existence of new performance parameters on urban road segment type 2/1 UD in the form of delay, and that can be an early indication as input in the update of IHCM 1997 and other research that the author has done before, as well as other authors who have also written about similar topics about this manual that is more than 20 years old (1997-2021), in analyzing the performance of road networks in Indonesia.