KAJIAN EMPIRIS HUBUNGAN PLATOON, JARAK ANTAR KENDARAAN DAN KESELAMATAN TRANSPORTASI JALAN

Abstrak

This study analyzes traffic characteristics along the Padang–Bukittinggi primary arterial corridor, focusing on vehicle platooning, spacing, and stopping sight distance (SSD) as operational safety indicators. Field data were collected through video recordings at Km 32, with vehicle classification, speed, and platoon formation identified using a critical headway threshold of ≤ 2.5 seconds.Traffic flow is dominated by light vehicles (> 70%), with medium heavy vehicles accounting for 25%, and large trucks and buses contributing less than 3%. Speed distribution within platoons is concentrated in the 40–60 km/h range, which increases capacity but reduces safety due to short spacing and insufficient SSD. Most vehicles in platoons operate with SSD ≤ 180 m, suitable for low–medium speeds but unsafe at higher speeds due to reduced safety margins. Unsafe spacing is prevalent, with 81.9% of vehicles in the Padang–Bukittinggi direction and 66.5% in the Bukittinggi–Padang direction, averaging only 26–29 m. Average spacing values of 26.88 m (Padang–Bukittinggi) and 28.57 m (Bukittinggi–Padang) correspond to speeds below 40 km/h. However, the dominant operating speeds are 40–60 km/h, highlighting a mismatch between actual spacing and safety requirements. This condition reflects dense traffic dominated by light vehicles, where drivers maintain short gaps to sustain flow, but at the expense of operational safety.