Alaska State Troopers credit the drug-related DUI arrest of an Anchorage driver, seen swerving on the Sterling Highway last weekend, to Report Every Dangerous Driver Immediately calls from other motorists.

Troopers said Monday they made a traffic stop on 22-year-old Austin Anderson's pickup near Mile 102 of the highway, after calls came in at about 5:30 p.m. Sunday saying he had crossed into the oncoming lane on "multiple occasions."

A caller reported at least two vehicles in the oncoming lane moved to avoid Anderson, troopers spokeswoman Megan Peters said in an email. One caller followed him for five miles while speaking on the phone with a dispatcher, she said.

"Investigation determined (Anderson) was driving under the influence of drugs," troopers wrote in a dispatch. "A search of the vehicle revealed other controlled substances."

Peters said there were six suspected Xanax pills in the pickup. Troopers matched the markings on the pills using a drug database, she said. The pills will also be sent to a lab for testing.

Anderson was held without bail at the Wildwood Pretrial Facility, on misdemeanor charges of DUI and fifth-degree misconduct involving controlled substances.