Drugs and alcohol were not factors in the Highway 101 crash earlier this week that killed San Luis Obispo High School student Alex Maier, according to the California Highway Patrol.

It could still take about a month for CHP investigators to determine and release their conclusions on what caused the 17-year-old to not see the BMW he hit while changing lanes, said CHP spokesman J.W. Townsen of the patrol’s San Luis Obispo office.

“If he was distracted by the radio or reached down for a second while he was merging — those are things we’ll probably never know,” Townsen said, since no witnesses have come forward. “We would know if he was using his cell phone because we can get records of cell phone use. But we have to substantiate that. And that takes time.”

Investigators are using physical evidence, like vehicle damage and skid marks, to determine what could have led to the crash.

Maier was driving a Ford F-150 truck south on Highway 101 just after 8:30 p.m. Monday while coming home from a soccer game when he accidentally clipped the front of a BMW sedan just south of California Boulevard in San Luis Obispo, according to the CHP. He was apparently attempting to merge into the fast lane, Townsen said. His truck spun out of control, then flipped onto its roof as it hit a guardrail. He died Wednesday night at Sierra Vista Regional Medical Center.

The driver of the BMW, 19-year-old Gianna Azzaro of San Luis Obispo, was not hurt. She has been cleared by the CHP and charges will not be filed against her, Townsen said. This moves the investigation into what Maier was doing as he changed lanes.

“We have to do more investigation work to see what the young man was doing prior,” he added, noting that Maier was wearing a seatbelt.

That includes looking into whether he was using a cell phone or was distracted by something else. Speeding isn’t likely, Townsen said, since Maier had just merged onto the highway, but if he was merging across all the lanes right away, that could be an aspect for investigators to look into.

No witnesses have come forward, and Maier wasn’t conscious at the scene to give a statement. Azzaro’s statement of what occurred has not been released. Neither vehicle had passengers.

“When a young person passes away, people want answers,” Townsen said. “We live in a small community here, and we don’t want to see any of our young people get hurt. When this happens, we want to make sure we look at everything.”

Memorial for Alex Maier planned for Saturday »

Reach Tonya Strickland at 781-7858. Stay updated by following @tstrickland on Twitter and checking out Facebook.com/SLOTribuneNorthCounty.