In undergraduate transportation engineering courses, traffic assignment is a difficult concept for instructors to teach and for students to learn because the concept involves advanced mathematical modeling and computations. A multiplayer game, called multiagent route choice, is designed to engage students in making route choices so that they can visualize how traffic gradually reaches a user equilibrium. In addition, the Braess paradox phenomenon, a concept not generally taught in undergraduate transportation courses, is embedded in the game for students to explore. A before-and-after comparison and a case-control study are performed to evaluate the effectiveness of the game as a curriculum tool. The impact of students' learning preferences is also investigated.