PHOENIX -- Phoenix police said a driver involved in a head-on collision that critically injured a 3-year-old child Saturday night may have been impaired by drugs.Edgar Martinez, 19, was booked into the Maricopa County Fourth Avenue Jail for four counts of aggravated assault and one count of endangerment.Phoenix police Sgt. Steve Martos said an Acura driven by Martinez was traveling northbound at a high rate of speed in the area of 31st Avenue and Acoma Drive.The Acura crossed into oncoming lanes and collided head-on with a southbound Nissan at approximately 7:15 p.m. The Acura rolled over onto its roof while the Nissan was forced backward.Martinez sustained minor injuries and was processed for possible impairment. The front-seat passenger sustained serious injuries that were not considered life-threatening.The driver of the Nissan was evaluated and found not to be impaired. He suffered serious injuries that were not considered life-threatening.Three children, ages 3, 5 and 11, in the Nissan were injured. The 3-year-old sustained life-threatening injuries and is listed in extremely critical condition, according to Martos.