STUDI PENINGKATAN RUAS JALAN ROBATAL – KETAPANG (STA 26+228-STA 36+228) KABUPATEN SAMPANG

Abstract

The Robatal-Ketapang road section (STA 26+228-STA 36+228) in Sampang Regency functions as a Class III primary collector corridor supporting inter-district mobility and goods movement. Improvement is required because the existing carriageway width does not yet satisfy the expected service standard, pavement deterioration is present, and drainage performance remains inadequate at several locations. This study evaluates the 2044 design LHR, determines flexible-pavement layer thickness using the Bina Marga 2024 method, sizes drainage channels for the design flood discharge, and estimates the Cost Budget Plan (RAB). The analysis uses LHR records for 2022-2024, DCP/CBR measurements, maximum rainfall at Robatal Station for 2015-2024, road geometry, DEMNAS-based topography, and unit-price data. The calculation produced a 2044 design LHR of 2,911 vehicles/day with a total of 7,196.33 light-vehicle units. CESA5 was 486,919.73 ESA5 and the subgrade CBR was 2.05%. The proposed pavement comprises 50 mm AC-WC, 60 mm AC-BC, 400 mm Class A LPA, and 175 mm subgrade improvement. The highest design discharges were 2.54 m3/s in segment G2-H2 and 2.21 m3/s in segment L1-M1. After 11% VAT and rounding, the total RAB is IDR 90,275,097,000.00. Accordingly, road widening, pavement strengthening, and drainage improvement should be implemented as an integrated package to improve road performance and limit deterioration associated with surface-water inundation.