Emission of CO, HC, NOx, and Soot from HDV Trucks and Buses using Remote Sensing in Indonesia

This study aims to measures and develops emission factors of CO, HC, NO x , and soot from HDV trucks and buses using remote sensing technology. The device applies absorption spectroscopy to directly measure vehicle exhaust emissions from the roadside, allowing traffic to continue without interruption. It records emission data for each vehicle in less than one second. Testing was conducted at 19 highway and toll road locations in Jakarta over 58 days, using a 2020 M752 version 3.1 remote sensing device. From a valid sample of 4,774 HDV trucks and 2,029 buses, the median emission factors for CO, HC, NO x , and soot for diesel HDV trucks are 3.65, 0.24, 3.51 and 0.117 g/km, respectively; for diesel buses, 3.70, 0.23, 5.53 and 0.122 g/km; and for CNG buses, 5.90, 0.91, 1.10 and 0.005 g/km. Across all three vehicle types, median emission factors decreased with newer production years. Median soot emissions are zero for diesel buses produced after 2015 and CNG buses manufactured between 2007 and 2015 and after 2015. Diesel and CNG buses emit less CO than diesel HDVs, with Isuzu diesel buses recording the lowest at 0.8 g/km. Diesel buses also record the lowest HC emissions, with Isuzu and Mercedes-Benz buses at 0.06 g/km. The lowest NO x and soot emissions are also observed in Scania and Zhongtong CNG buses, with NO x around 0.3 g/km and soot at 0 g/km. The findings of this study can inform air quality regulations, support urban transportation planning, and raise awareness of the health impacts of pollution, particularly from the transport sector in Jakarta, Indonesia.