Possible Clues:

• Shift direction suddenly
• Take a sudden turn
• Turn off course
• Avoid another car, say
• Dodge a pothole, perhaps
• Looking back, father hides direction of swing
• Turn sharply, I hope because you decided at the last minute to stop at that ice cream place on the side of the road!!!
• Swerve erratically, to some extent
• Turn aside
• Alter one's course