DOI RECORD
GPS Floating Car Data for Road Emission Temporal Variability in Poland
Abstract
Temporal variability factors (TVFs) are required to disaggregate annual road transport emissions to the temporal resolution needed by chemical transport models, yet locally representative profiles are often unavailable. This study evaluates GPS-derived floating car data (FCD) as a source of TVFs in Poland. Two FCD datasets (2017 and 2024) were compared with traffic counts from the traffic count network using GPS penetration rates, expansion factors, and derived temporal profiles. The 2024 dataset showed strong agreement with observed traffic volumes across road classes, the 2017 dataset performed substantially worse. GPS-derived TVFs accurately reproduced diurnal and weekday-weekend traffic patterns, despite minor temporal lags. SCPR observations exhibited considerable temporal and spatial variability (coefficients of variation 0.15-0.45), highlighting limitations of generalized profiles. Compared with GPS-derived TVFs, CAMS-based profiles produced hourly NOₓ emission differences ranging from 0.5 to 2.5. These results demonstrate that FCD provides a robust and scalable source of TVFs for air-quality modelling.