AMERICAN FORK — Police believe alcohol was a factor in an accident that sent one woman to the hospital via helicopter and closed I-15 for nearly a half-hour Friday.

The woman, in her 40s, was traveling south on 500 East in American Fork and was reportedly weaving in and out of traffic, nearly running off the road, said American Fork Police Lt. Sam Liddiard.

Residents who were following the woman around 1 p.m. called 911 to report her erratic driving, worried it was due to a medical problem.

The woman stopped at a green light at 500 E. State. She sat through the red light and the next green light, then at the second red light she sped off, Liddiard said.

At that point, she would have had to turn to her right to access the 276 onramp to I-15, but instead she skidded off the road, barely missing a pond and a tree, and rolled her Lexus, which ended up on its side.

Liddiard said she was conscious and breathing when emergency personnel arrived and extricated her from the car.

She was flown to Utah Valley Regional Medical Center with minor injuries.

Northbound I-15 was shut down for nearly 30 minutes while a medical helicopter landed to transport the woman. But even after being opened, traffic was backed up until the Lindon exit, three exits south.

Alcohol is believed to be a factor in the crash, Liddiard said, and officers are still investigating the case and will most likely be referring it to prosecutors for charges.

He thanked those who called 911 and said he was grateful that most people carry cell phones, which meant officers were already on their way to stop the woman from crashing when she actually crashed.

"It's very fortunate that no one else was hurt," Liddiard said.