Incorporating Eco-hauling and the Big Room approach emerges as a viable strategy for curbing carbon emissions in the construction phase. Eco-hauling optimises heavy vehicle operations to reduce emissions and costs through strategic, tactical, and operational measures, emphasising fuel efficiency and sustainable practices. On the other hand, the Big Room approach, rooted in lean management principles, promotes collaborative decision-making, transparent communication, and shared goals among project stakeholders in the construction phase. Thus, synthesising Eco-hauling with the Big Room approach provides a collaborative environment that enables streamlining processes, anticipating constraints, resolving bottlenecks, and reducing idle and operation time, leading to lower emissions and environmental sustainability. A hauling operation within a road project was analysed via a case study method to explore the synthesise result. Discrete event simulation (DES) and AnyLogic software were employed to evaluate different scenarios, taking into account variables such as the number of dumper trucks, payload capacity, and speed. The primary objective was to assess the carbon emissions for each scenario. From an initial set of 30 scenarios, expanded to over 400, Stat-Ease software identified two scenarios with the lowest CO2 output, focusing on minimising the operation total time in one case and without considering the operation total time in the other. The outcomes contribute critical insights into sustainable logistics practices, offering pragmatic pathways for enhancing hauling operations and addressing environmental concerns in construction projects.