Impacts of urban transit system development on modal shift and greenhouse gas (GHG) emission reduction: A Khon Kaen, Thailand case study

The objectives of this study are: (1) to apply an Urban Transport Planning Model (UTPM) to predict the current and future travel demand characteristics in Khon Kaen City (KKC), and to determine the potential GHG emission reductions as a result of implementing a complete mass transit system consisting of five lines, and (2) to evaluate the proposed scenarios along with some recommendations in terms of policy implications. Four-step UTPMs were developed and applied to predict the travel demands. Consequently, a bottom-up 2 approach was adopted to project the GHG emissions resulting from each established scenario in the years 2016 through 2046. The proposed five-line mass transit system was compared with the baseline (no-project). The results showed that the proposed project would likely cause a shift from private modes of transportation (motorcycles (MC) and passenger cars (PC)) to public transport (PT) over the projected time period (30 years). It could also improve the traffic and transport conditions in the study area by reducing the Vehicle Kilometers of travels (VKT), Vehicle Hours of travels (VHT), Volume-to-Capacity (V/C) ratio values, increase the average travel speed and reduce CO2 emissions. However, the impact of PT transport development is still limited.