The scientists built a model called GET-0 to study how transportation in Canada affects different parts of the economy. They looked at how different types of transport, like road and rail, connect with other sectors like agriculture or energy. By using Canadian data, they ran simulations to see how government policies impact things like intercity trade and inter-industry relationships. Through these simulations, they discovered how policies related to taxes and the environment can influence the transportation sector and the economy as a whole in Canada.