Energy Intensity of Urban Passenger Transport at Different Occupancy Levels

Urban passenger transport is a significant source of energy consumption and greenhouse gas emissions; assessing it requires distinguishing between a vehicle’s energy characteristics and the efficiency of the transport service provided. The objective of this paper is to develop and apply a harmonized framework for comparing energy intensity and emissions across urban passenger transport modes and propulsion technologies, accounting for city type, operating period, and vehicle occupancy. The baseline analysis at the vehicle level was supplemented by an assessment incorporating nominal capacity, occupancy rate, and passenger numbers derived from the source dataset. Additionally, a sensitivity analysis was conducted for standardized capacity utilization levels of 25%, 50%, 75%, and 100%. The research questions guiding the analysis were formulated as follows: 1. How do the energy intensity and emissions of the analyzed urban passenger transport modes and propulsion technologies vary depending on the type of city and the time of day? 2. How does accounting for the nominal capacity and occupancy levels of vehicles alter the results of comparisons when indicators are calculated per passenger-kilometer? 3. How do the energy intensity per passenger-kilometer and the ranking of transport modes change at standardized capacity utilization levels of 25%, 50%, 75%, and 100%? The results demonstrated that accounting for occupancy significantly alters the interpretation of intermodal comparisons. During peak hours, average TTW energy consumption per passenger-kilometer was lowest for heavy rail (0.111 MJ/pkm), BRT (0.156 MJ/pkm), and large buses (0.176 MJ/pkm), whereas for passenger cars, it was 1.162 MJ/pkm. During off-peak periods, reduced occupancy increased the energy intensity per passenger for most public transport modes; this effect was most pronounced for midi-buses, where the figure rose from 0.223 to 1.511 MJ/pkm. Scenario analysis confirmed that a ranking based on energy consumption per vehicle may differ from one based on transport output. Therefore, indicators at the vehicle and passenger-kilometer levels should be treated as complementary when evaluating propulsion technologies and modes of transport.