Energy efficiency evaluation from micro trip database of HDV bus tracking system

Fuel consumption (L/100 km) is one of the most important parameters for assessing fuel economy and energy efficiency in the road transport sector. However, the fuel consumption database for Thailand heavy duty vehicles (HDVs) is usually collected from road-side surveys, as whole trip summaries, e.g., total consumed fuel quantity, and measured driving distances. Therefore, the effects of trip details, e.g., topography, route curvature, and driving style on fuel consumption, cannot be calculated. Nowadays, the modern vehicle tracking system, which can acquire vehicle traveling information at every second, including real-time fuel consumption, provides numerous sets of micro trip data. Therefore, this study aims to indicate important parameters effected on the fuel consumption of HDV buses, from the analysis of micro trip databases. Out of a number of fixed HDV buses routes, the Bangkok – Nakhon-Ratchasima route (about 300 km) was selected from seven HDV bus routes because this route has sufficient elevation gain (uphill) and elevation loss (downhill) for the analysis. From the analysis results, the correlation between fuel consumption and elevation gain was distinctively observed, while the relationship with other energy-related parameters were not observable. During the vehicle ascending, fuel consumption increased linearly as 0.75 L/100km by an elevation gain in m/km (? = 0.75? + 29.71). However, from elevation gain above 50 m/km fuel consumption fluctuated around a constant value of 59.03 ± 7.25 L/100km.