Factors affecting commuter rail energy efficiency and its comparison with competing passenger transportation modes
As concerns about the environmental impacts and sustainability of the transportation sector continue to grow, modal energy efficiency is a factor of increasing importance when evaluating benefits and costs of transportation systems and justifying future investment. Poor assumptions on the efficiency of the system can alter the economics of investment in commuter rail. This creates a need to understand the factors affecting commuter rail energy efficiency and the comparison to competing passenger transportation modes to aid operators and decision makers in the development of new commuter rail lines and the improvement of existing services. This thesis describes analyses to further understand the factors affecting the current energy efficiency of commuter rail systems, how their efficiency may be improved through implementation of various technologies, and how their efficiency compares to competing modes of passenger transportation. After reviewing the literature, it was evident that past studies often conducted energy efficiency analyses and modal comparisons using methods that favored one energy source or competing mode by neglecting losses in the system. Therefore, four methods of energy efficiency analysis were identified and applied to 25 commuter rail systems in the United States using data from the National Transit Database (NTD). Using the same database, an analysis of trends in energy efficiency exhibited by the United States commuter rail systems was conducted. To understand the effects of congestion, traffic heterogeneity, operational parameters, and infrastructure characteristics on energy efficiency of passenger trains, single and multi-variable analyses were conducted. Simulations in Rail Traffic Controller (RTC) provided energy consumption results that were used in the statistical analyses. The results illustrated the effects of congestion due to increased freight and passenger traffic on a single-track freight-owned railroad. The effect of alternative scheduling patterns on energy intensity was analyzed through a case study of operations on one existing commuter rail line. Using the Multimodal Passenger Simulation Tool (MMPASSIM), the energy consumption of the current operations and proposed schedules of local, zonal, skip-stop and express train stopping patterns during a weekday peak period were simulated. A trade-off between improved passenger service through reduced travel times and energy consumption was evident in the results. MMPASSIM was also used to simulate the effects of technologies and strategies to increase energy efficiency and improve service levels. Changes such as electrification, driver advisory systems, equipment modifications, and slow zone reductions were evaluated for their effect on energy efficiency and service metrics. Finally, MMPASSIM was used to compare the energy intensity of the same commuter rail service to competing modes of passenger transportation for equivalent commuter trips. The rail service was evaluated under local, zonal, and skip-stop patterns and compared to automobile and bus trips under off-peak and peak highway congestion levels. Load factor sensitivity charts were developed, showing lines of equal energy intensity of rail and competing modes across a range of modal load factors.
Commtuer, Rail, Energy, Efficiency, Competing, Mode, Factors, Affecting, Bus, Auto, Car, Simulation, Model, Performance, Methods, Trends, Congestion, Geographic Information System (GIS), Grade, Gradient, Highway, Transit
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign