Road Safety Evaluation on Collector Road Section of Siluk-Panggang, Yogyakarta, Indonesia

The Siluk – Panggang road section is a provincial road that functions as a primary collector road. The sharp horizontal alignment and steep vertical alignment conditions make this road section potentially cause traffic accidents. Therefore, the objective of this study is to evaluate the road geometric conditions of the roads to enhance road safety. Specifically, this study includes identifying the types and number of accidents, carrying out Road Safety Inspections (RSI) according to the 2005 Bina Marga Technical Guidelines, and analysing road geometry (horizontal and vertical alignments) with AutoCAD Civil 3D software which is further compared to the 2021 Bina Marga Regulation concerning Road Geometric Design Guidelines. Based on the RSI results, it is known that this road has the number of lanes and lines, as well as the width of the shoulder according to the requirements, but the width of the traffic lane does not meet the requirements. Based on the geometric modelling of the road, 12 bends can be identified, where 46% of the bend radius does not meet the requirements. In addition, vertical alignment consists of 14 curves with 7 convex curves and 7 concave curves. However, 40% of slopes exceed the maximum and 57% of K values do not meet the requirements. Therefore, geometrically this road has a high potential for accidents.