Bangkok Port, located within metropolitan areas face increasing challenges related to traffic congestion, 
land-use inefficiency, and environmental externalities. Bangkok Port (Khlong Toei Port), Thailand’s primary 
international river port, exemplifies these challenges, due to its inner-city location and heavy reliance on 
truck-based freight transport. This study assesses traffic impact from development of a multi-storey 
distribution center (DC) within Bangkok Port. It evaluates its impacts through a comprehensive Traffic 
Impact Assessment (TIA) framework integrated with smart port and port decarbonization strategies. The 
objective of the paper is to analyze, assess and forecast the current level of urban traffic congestion at 
specific intersections in Bangkok Port, using urban planning perspective. The traffic congestion measures 
and strategies have been recommended. A mixed-method research approach is adopted, by combining 
traffic volume surveys, origin–destination analysis, passenger car unit (PCU) conversion, level-of-service 
(LOS) evaluation, and long-term traffic forecasting over a 30-year horizon. Scenario analysis compares 
baseline conditions with a redevelopment scenario featuring vertical land-use consolidation, truck 
appointment systems, and external buffer yards. Results indicate that the proposed DC development can 
significantly reduce internal truck circulation and queuing, maintaining acceptable LOS levels (C or better) 
on critical road segments. Importantly, congestion reduction yields measurable environmental co-benefits. 
It reduces truck idling of 10–30 minutes per trip correspond to annual savings of approximately 620–1,860 
tCO₂ and 3–9 kg of PM2.5 from freight vehicle operations. The findings demonstrate that integrating traffic 
management with vertical port redevelopment, not only improves logistics efficiency, but also delivers 
tangible decarbonization and local air-quality benefits. Further, the redevelopment reduces logistics costs 
per GDP. The study also provides policy-relevant insights for sustainable redevelopment of inner-city ports 
in rapidly urbanizing regions.