To increase a precision of a side impact test for vehicles.

The vehicle traction device is constituted such that a dolly 13 is only located in the rear of a test vehicle 14 in moving direction when testing the test vehicle 14, and that an arm 15 is provided to the dolly 13 to push the test vehicle 14. The vehicle traction device accelerates the test vehicle 14 by pressing it while a desired posture of the test vehicle 14 is kept with an attachment 16 provided on the arm 15. Since the dolly 13 is only located in the rear of a test vehicle 14 in moving direction when testing the vehicle, if the dolly 13 is separated from the test vehicle 14 in consideration of a stopping distance of the dolly 13, the test vehicle 14 moves closer to a barrier 17. Therefore, the device makes the test vehicle 14 clashed into the barrier 17 without changing its posture by an external forces after separating the dolly 13 from the test vehicle 14.