Abstract: In order to quantitatively study mandatory lane-changing behavior of vehicles in a small section between mountainous expressway tunnel and interchange exit, a game model was proposed in conformity with characteristics of mandatory lane-changing behaviors. Firstly, lane-changing process of off-ramp vehicles and characteristics of such a decision were analyzed. Secondly, considering influences of driving style on such behaviors, a game model was put forward between these vehicles and following ones on target lanes by using dynamic game theories of incomplete information, and a game payoff matrix was established in consideration of the time and security benefits of game players. Then, refining Bayesian Nash equilibrium under forced lane-changing strategy was calculated. Finally, the validity of lane-changing game model was verified through Netlogo simulation platform. The results show that the optimal lane-changing strategy is that off-ramp vehicles, in spite of different driving styles, should choose forced lane change, while those following ones on target lanes should slow down to give way to them. Drivers with different styles vary significantly in terms of distance between lane-changing completion point and interchange exit, and that distance for aggressive drivers is generally greater than that for cautious ones.

Key words: tunnel to interchange, small spacing, driving behavior, mandatory lane-changing, signal game