Which arm signal tells you that the car you are following is going to pull up?

The arm signal indicating that the car you are following is going to pull up is typically the driver's left arm extended out of the window and bent at a 90-degree angle, with the hand pointing upwards. This signal is used to indicate a right turn or a lane change to the right. It's important to stay alert to these signals to ensure safe driving and maintain proper distance from the vehicle ahead.