Waze is a GPS app owned by Google which crowd-sources commuting patterns of its users (called Wazers) and provides the quickest path from point A to B. Once one route gets too crowded, Waze is supposed to move you to a newer, faster path. It's not perfect, but it's pretty good. It provides users with an estimated time of arrival which, in my experience, has been exceptionally accurate.

As a reporter in Los Angeles for the last 27 years, I thought I knew every backstreet, every shortcut.

Drivers in Los Angeles pride themselves on their ability to strategize the daily commute. Every day presents a new challenge: Find the best shortcut, the secret alternative route, to shave off precious minutes from a cruel trek. "Saturday Night Live's" "The Californians" is played for laughs , but it rings true.

"We spent billions of dollars expanding the 405 to 10 lanes—why don't they take that?" asked an agitated Tam Wynn. Her home is not far from the 405 and 101 interchange, considered the most congested in the nation. Wazers and other GPS app users drive down her street as an alternate route beside the 405, a way to shave off some time using Sepulveda Boulevard, a popular nonfreeway route from the San Fernando Valley to LA's west side. "I realize they're obeying the law, but as homeowners we can push back, too."

Wynn and her neighbors fought for a left-turn arrow to slow down traffic coming into their neighborhood. But she noticed an uptick of lawbreakers two months ago, people blowing through the arrow, along with other drivers discovering her street. She blames Waze, and she began taking photos. "We put a camera down there," she said, "and we clocked 600 cars running it in three hours."

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Now her homeowners group is asking the LAPD for help. Good luck with that.

"There's nothing illegal about it, unless they're driving unsafely or breaking any of the laws, so all we can tell them is 'sorry,'" said LAPD Officer Troy Williams, a motorcycle cop from the Valley Traffic Bureau. However, he said he is citing more drivers breaking laws. I witnessed him writing tickets for drivers who were making a left turn up a secret backway. The move is legal—except between 7 a.m and 9 a.m. on weekday mornings.

"If the app tells a driver to go down a street, and there's a sign saying you can't turn, the sign takes precedence over the app," he said.