This chapter focuses on the role transportation resistance plays in explaining the amount of transportation and the mode of transportation. The important forms of transportation resistance are travel time, travel costs, and the effort that can be involved in moving. Many transportation policies deal with transportation resistance. Policymakers often invest in new road infrastructure to reduce resistance due to congestion. But they also apply charges, for example on fossil fuels, to entice people to buy more fuel-efficient vehicles, among other things. This chapter focuses on the role of resistance in both passenger and freight transport.