The driver of a vehicle ahead of you is signaling to merge into your lane. You should

Explanation

Be a courteous driver, not an aggressive driver. When a driver ahead of you signals his or her intention to merge into your lane, slow down and leave enough space for the lane change to be completed safely. (A recent survey on aggressive driving by the AAA Foundation for Traffic Safety found that about one out of four American drivers had deliberately tried to block another vehicle from changing lanes.)