Understanding travel behaviour in transportation system is key challenge to calibrate and simulate the usage of urban mobility networks. We define in this work a path-based centrality based on the simplicity of the path between two locations in road network. Analyzing a huge dataset of GPS points of more than 20'000 vehicles and 170'000 trips, we reconstructed the real trajectories and estimate the degree of simplicity of each of them. Interesting insights of drivers' behaviour came from the comparison with the shortest and the simplest path. This allowed us to categorize trips according with their complexity and extract general behavioural relation among drivers. Finally, we measured the effect of considering simplicity as path-choice factor influences the distribution of road usage and the link betweenness.