The fiscal policy of Sri Lanka reflects a substantial portion of its annual capital expenditure on road infrastructure projects, notably after the post-war period from 2010. The economic viability of road projects against a threshold Economic Internal Rate of Return (EIRR) ranging from 9 to 12% at their reporting stage demonstrates very high values yet the contribution of which to the country's Gross Domestic Product (GDP) is not reflected in the economic growth rates. This paper investigates the extent to which road investments in the past decade have contributed to economic growth. Primary and secondary data obtained from public road sector entities were analyzed focusing on fund allocation for road network construction among various state agencies. A multi-year benefit calculation, incorporating the Value of Time saving (VOT), Vehicle Operating Cost (VOC) saving, and Accident Cost saving, was conducted. The paper compared GDP growth rates across the economic sector identifying growth potentials in specific areas and assessing macroeconomic implications using the Harrod-Domar (HD) model. The findings indicated an overstatement of predicted benefits in the road sector during the feasibility assessment stage, revealing that the anticipated economic benefits had not materialized. The study facilitates the prioritization of road investments with the highest growth potential, guides budget allocations for the next 5–10 years, and advocates for diversifying road sector investments to maximize economic benefits to the economy. Furthermore, the study's insights contribute to achieving a better balance between road infrastructure and other sectors for overall economic development.