NewsOperation Safe Roads


Operation Safe Roads: Are leading lefts, lagging lefts safer on the roads?

Posted at 4:39 AM, Feb 22, 2022
and last updated 2022-02-22 23:41:53-05

GOODYEAR, AZ — There are many ways drivers can make a left turn at an intersection in the Valley — lagging, leading, protected, and permissive turns — and over the years, Operation Safe Roads has investigated the many ways drivers can make the move.

Often, it is different in each city, and at each intersection. But it is not as random as drivers may think.

"Roughly... year and a half has been... in Goodyear, in particular, has been a significant increase in traffic," said Goodyear Traffic Engineer Hugh Bigalk.

He told ABC15, the city decided to make a big move in the last few months and changed lagging lefts to leading lefts in nearly two dozen spots.

A lagging left allows drivers to turn after the green light. A leading left gives drivers the opportunity to turn left before traffic moves through the intersection.

"Where in a lagging case... the left cars waiting to turn left will back up in the left turn lane, fill it up, and then continue to back up the through lane," Bigalk said.

Bigalk was asked if safety was the reason behind the move.

"There isn't a distinct difference between leading or lagging left turns," Bigalk described. "It seems to be pretty equal based on the studies we've read."

He tells ABC15 that the decision is more about easing congestion, which in turn, can reduce possible crashes. It is more the type of left turn where safety becomes the focus.

"I haven't really noticed," said Valley driver Alyssa Kruger. "Maybe I'll notice now that I'm thinking about it."

ABC15 Traffic Anchor Megan Thompson hit the streets to ask drivers, like Kruger, if they notice the different movements at intersections on their ride.

We asked Valley visitor Kirk Brandt whether he really thinks about the safety of turning left at intersections.

"Not really," he responded. "I'm pretty aware of my surroundings."

A flashing arrow indicates drivers should yield and proceed only when safe. There is also a protected green arrow, meaning drivers making that left turn are the only traffic moving through the intersection.

"It depends on traffic. Like obviously, if it's heavy traffic... if there's a green arrow, you can get through easier and clearly more safely," Brandt said.

ABC15 reached out to Street Transportation departments around the Valley, like Mesa and Phoenix.

Both said the same as Goodyear, which was that there is not a distinct safety difference in lagging or leading lefts, as in when drivers get to turn left.

But Mesa stressed a recent study by the Federal Highway Administration in 2020 found flashing left-turn arrows reduced the number of crashes by about 20%. The city has been installing this at intersections in recent years to improve safety.

Have a road issue or a question for Operation Safe Roads? Call 833-AZ-ROADS or email