The traffic assignment problem (TAP) has been studied for a long time, and the user equilibrium is one of its basic models. Some researchers use electrical current to simulate traffic flow to solve the user equilibrium problem, as measuring electrical current flow is faster than computing traffic flow. However, in past researches, the associated circuit problem is solved by software simulation, and the physical hardware systems have not been implemented. We designed the algorithm for physical circuit and implemented a microprocessor system to control the whole circuit and execute the computation. The results show that the difference between physical flow and theoretical flow is small, and the feasibility of a hardware system for large circuits is thus verified.