Lifecycle Environmental Impact of High-Speed Rail System in the I-45 Corridor

摘要

The Houston-Dallas (I-45) corridor is the busiest route among 18 traffic corridors in Texas. The expected population growth and the surge in passenger mobility could result in a significant impact on the regional environment. This study uses a life cycle framework to estimate the net change in environmental impact with the development of a high speed rail (HSR) System along the I-45 corridor. The study follows ISO 14040 principles and standards of life cycle assessment, and uses SimaPro 8.5® software and the Ecoinvent 3.3 inventory database. Infrastructure construction, vehicle manufacturing, system operation and end of life phases are included in the life cycle assessment. The energy and emissions of the system are evaluated per vehicle/passenger-kilometers traveled and compared with the existing transportation modes. Vehicle component accounts for 14.50 kgCO_2eq/VKT, of which fossil-fuel usage during operation is the primary contributor with 98% of the greenhouse gas (GHG) emissions. For the infrastructure component, 56.76% of GHG emissions result from the material extraction and processing phase (23.75kgCO_2eq/VKT). Life cycle CO_2 emissions of this system are 40% lower than comparable systems in Europe, Asia and North America. The minimum ridership levels required to offset the environmental impact from conventional modes of transport are around 12% and 27% for GHG emissions and NOx emissions respectively.