Various infrastructure investments lack sufficient finance mainly because the sources of revenue rely on user charges. High-speed rail requires regular maintenance and repairs to maintain timely operation; however, these costs are not sufficiently covered by revenue from user fees alone. We propose that the infrastructure revenue should include not only user charges but also tax revenues created by the spillover impact of the high-speed rail entering the region. Using a difference-in-differences method, we measured the impact of the French high-speed rail line “LGV Est” on local property and income tax revenue in the municipalities or “communes” through which the line passes. We compared three pairs of municipalities in the Grand Est region to establish whether LGV Est had a significant impact on local tax revenue. The results demonstrated a statistically significant impact of the HSR line on property and personal income tax revenue across the different implementation and operation periods. We found that the HSR infrastructure had a greater relative impact on property tax than on personal income tax, with increases of up to 182% and 56%, respectively. We estimated that the total spillover tax revenue for LGV Est could contribute €300mn in revenue to the infrastructure operator. Our findings confirm the potential of redirecting the spillover tax revenue of infrastructure projects to the infrastructure operators, allowing for greater involvement of the private sector in investment and better coverage of maintenance costs. Better maintenance of large HSR networks is essential for reliable operation. Spillover effects, if properly channeled, could increase private sector investment in public goods projects while keeping user fees low, furthering the transition to greener, more inclusive transportation infrastructure.