According to documents submitted by the Transport and Logistics Bureau to the Legislative Council's Railway Matters Subcommittee, after examining various non-heavy rail transportation systems in the market regarding passengers carried, climbing ability, route flexibility, infrastructure, and operational equipment requirements, the authorities confirmed the adoption of a smart green collective transportation system to develop the west section of the South Island Line, replacing the original heavy rail plan. This approach is technically feasible, and in the future, financial arrangements will be evaluated, including further optimizing the route and improving cost-effectiveness, with the hope of starting detailed planning and design by 2025, aiming to commence preliminary construction work by 2027, in line with the timetable for the reconstruction of Wah Fu Estate.

The bureau pointed out that the terrain along the west section of the South Island Line varies, and the heavy rail's climbing ability is limited. Some sections may need to go deep underground, leading to unsatisfactory transportation and cost-effectiveness. Therefore, they are actively exploring suitable alternative solutions to enhance the project's technical feasibility and overall cost-effectiveness.

The Transport and Logistics Bureau stated that the planned smart green collective transportation system is a medium-capacity system, primarily operating on dedicated elevated bridges, completely separated from surface traffic, unaffected by existing road traffic. The initial suggestion includes that some routes adopt tunnel design.