Talk about nerves of steel.

When his father began suffering seizures while driving down the highway in Peabody just before noon on Saturday, a 12-year-old Dracut boy grabbed the wheel and steered his father and 9-year-old sister to safety, according to State Police.

The family has requested anonymity.

“The word hero may be overused in our society, but this boy is surely that, and then some,” said David Procopio, State Police spokesman, in an e-mail.

The boy guided the car, which was heading southbound on Interstate 95 in Peabody, into the breakdown lane and hit the brakes. He then took his father’s cellphone and called 911.

He was not sure exactly where he was, but he calmly described his surroundings to a state trooper while troopers and cruisers in the area searched for the vehicle, according to a State Police statement.

Electronic attempts to locate the cellphone placed it somewhere near Peabody, Procopio said, but that area has several highways.

When police found the vehicle on a ramp at the intersection of Interstate 95 and Route 128 in Peabody, the father was unconscious.

That stretch of the highway, said Trooper Todd Nolan, is “flat, wide, free of debris, and people go really fast on it.”

“The boy’s poise, clear thinking, and decisive action potentially saved this family from a tragedy,” said Procopio.