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The road alignment planning process is a very complex and time consuming task.The final alignment selected during the planning and design process could have major impacts on project construction and life-cycle operation costs.It is well recognised that the greatest opportunities to contain overall costs and minimise environmental and social impacts are during the planning stage.Traditionally, route selection has relied heavily on planners professional experience and judgement.The increasing environmental and construction cost concern have made the route selection process more complex than ever before.The lack of purpose-specific tools has greatly limited the planners capacity to consider all the data and the numerous constraints and to compare and analyse all viable alternatives within a limited time period.An intelligent road planning tool has been specifically developed to address the complex planning problem.The planning tool begins with a digital terrain model of the study area and other relevant geographical information, and then by defining the input parameters such as design standards and cost parameters such as cut/fill rate and bridge/tunnel unit costs and other constraints such as avoid zones and crossing requirements, the planning tool will automatically search all possible alternative alignments within the study area.Unlike the traditional planning approach, it explores millions of alternatives and quickly returns a range of 3D alignment models with automated earthworks; structures such as bridges,tunnels attached, and associated volumes and costs calculated.The process can be operated iteratively with new constraints added during the planning process which can provide a swift response to public feedback and re—evaluate alternatives within hours instead of weeks and months.It also empowers planners and designers to minimise the negative environmental and social impacts of road projects,whilst reducing construction and life-cycle operation costs.When the project approaches the construction phase, it can also be used as a valuable engineering tool to refine the final alignment within the corridor, or just perform a vertical optimisation to reduce earthworks and other construction costs.This paper illustrates how the intelligent road planning tool can shorten the planning time, increase productivity and reduce project cost, whilst achieving results that have lower environmental and community impact than traditional methods.A number of case studies are presented to demonstrate the innovative planning process and its adaptability to different project needs such as low-grade mountainous roads and high standard state freeways.