Geometric analysis of potential accidents on the Sentolo-Nanggulan road, Yogyakarta.

The Sentolo-Nanggulan road is located in Kulon Progo Regency and is a provincial road with a primary collector road function. It is a geometric road with sharp bends and steep inclines, making it potential for traffic accidents. The Kulon Progo Resort Police recorded 58 accidents with 81 victims on this road in 2018-2020. Therefore, this study aims to analyze the geometrics of the Sentolo-Nanggulan road, particularly the horizontal and vertical alignments, compared with the 2020 Highways Guidelines. A road safety inspection (RSI) survey was conducted to analyze the existing road's horizontal and vertical alignments. Furthermore, both RSI and secondary data from the Geographic Information Agency (BIG) were employed to analyze the horizontal and vertical alignments using AutoCAD Civil 3D software. The RSI results unveiled the traffic lane width for the Sentolo-Nanggulan road of only 2.7 meters, thereby not meeting the minimum requirements for collector roads (3.5 meters), poor visibility in some horizontal alignments and vertical alignments, lack of street lighting, and road drainage channels not maintained. Furthermore, AutoCAD Civil 3D software analysis resulted in 70% horizontal alignments and 50% vertical alignments on the Sentolo-Nanggulan road not meeting the requirements. In short, there is a high risk of accidents. [ABSTRACT FROM AUTHOR]