Highway investment can boost the economy, but the impact is not as big as previously thought. This study looked at the relationship between transportation investment and economic development from a transportation perspective. They measured the physical size of highways instead of just the money spent, and considered both quantitative and qualitative indicators. The results showed that transportation investment does have a positive effect on the economy, but it is relatively small. The impact is seen in both the short-term and long-term, with a slight increase in economic development.