Researchers used a detailed model to study how improving transportation in different regions of Egypt could affect the country's economy. By analyzing how changes in transportation costs between areas could impact trade and economic growth, they found that projects with the potential to boost the overall economy might also lead to uneven development across regions. This means that efforts to make the country's transportation system more efficient could result in some areas growing faster than others, posing a challenge for policymakers trying to balance national progress with equal development among different regions.