“…A second set of studies takes a mathematical programming approach, studying user equilibrium and market equilibrium in the context of traffic flows and credit price under different assumptions, for example fixed/elastic demand, homogeneous/heterogeneous travellers, different initial credit allocations (e.g. Nie, 2012;Wang, Gao, Xu, & Sun, 2014;Xiao, Qian, & Zhang, 2013;Yang & Wang, 2011). The third domain consists of studies that empirically investigate travel behaviour under TC schemes at the individual level.…”