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Fleet Management Information for Sweeping Professionals


Attenuator Trucks: Taking the Hit to Save Sweepers

by Sean Emery, Southern California News Group
photos by Mark Rightmire, Orange County Register

Every week fatal and/or near-fatal accidents involving sweepers are reported. Attenuator trucks, also known as 'safety cushion trucks,' have saved the lives of many sweeper operators.

Attenuator Truck

Frank Ramirez spotted the BMW in his rearview mirror darting up behind him as he sat in his Caltrans vehicle at the tail end of a street-sweeping convoy on the northbound I-5 Freeway in Orange. He watched as it changed lanes before disappearing from sight. Then, in his words, a "Bang!" and a "Boom!" Time slowed down as the other driver struck yet a third vehicle before caroming into a fourth – the side of Ramirez's truck, pushing it into a sound wall.

No one was seriously hurt, and Ramirez – in the seat of one of Caltrans so-called "shadow" vehicles or trucks with the big yellow cushion on its rear – had done his job. He had taken a hit so the workers cleaning the freeway ahead of him didn't, walking away from yet another collision in his nearly 40-year career.

"I asked her, 'What did you see? I had flares out there?' " Ramirez recalled. "She said, 'Oh, yes, I saw the flares, but I was just wondering what they were there for.' "

"She wasn't paying attention," Ramirez chuckled, shaking his head. "I don't know what she was doing."

A constant but usually unnoticed fixture on freeways, the drivers of the shadow trucks serve as blockers for the street-sweepers, the California Highway Patrol cruiser often with them, and the trash-removing crews that walk ahead at the front. Without the street-sweeping convoys, Southern California freeways would be an minefield of debris. And without the shadow vehicles, even the imposing sweepers themselves would be targets for inattentive or intoxicated drivers.

In 2008, Christopher Laurie, the 33-year-old son of well-known Pastor Greg Laurie, died after rear-ending the backup shadow vehicle in a five-truck crew on the eastbound 91 Freeway in Corona. Investigators determined that Laurie had been speeding and unable to stop in time to avoid the crew. No worker was injured. Since 1993 at least, according to Caltrans records, no worker has been killed while on a sweeper train.

CalTrans Attenuator But there have been at least a dozen major accidents involving the 650-strong shadow-truck fleet across California over the past five years, according to Caltrans officials. Those figures don't include the lesser collisions, such as Ramirez's, or the constant, teeth-rattling near-misses.

"It was spooky at first," Ramirez admitted of his initial experiences decades ago as a shadow-truck driver. "You were on edge, it was stressful. But after you did it a few times, you calm down and you tell yourself where to pay attention."

With last year's state Senate bill earmarking an additional $50 billion-plus to fix roadways and bridges in upcoming years, Caltrans officials say, the sweepers and their teammates will be doing even more sweeping. And while state law now requires drivers to move over or slow down when passing Caltrans vehicles with their amber lights flashing away, the maintenance workers know full well that potential trouble lurks.

Caltrans supervisors in the Inland Empire noted that they often schedule cleanup work for the weekend in order to avoid commuter traffic. Sweeper crews across Southern California usually have a CHP unit with them. "There is probably a lot more respect to red and blue lights compared to the yellow lights," said Jim Rogers, a maintenance manager with Caltrans' Inland Empire division.

The shadow vehicle is there not only to protect the crews. If a car were to get around a shadow vehicle, a collision with the sweeper truck likely would result in far greater damage to the civilian car. "Not only is it (for) the safety of our own employees, it is (for) the safety of the public," Rogers said.

On a rainy morning in late May, Jorge Negrete walked out of the daily safety meeting at an Orange maintenance yard and took a last check of his bright-orange shadow vehicle. The largest safety vehicle used by Caltrans, the shadow truck carries a large electronic sign that flashes an arrow directing drivers, and a device the agency calls an "attenuator" that is lowered during sweeping operations. "Inside, it is a big cushion," Negrete says. The attenuator holding the cushion is eight feet wide and can be eight to 15 feet long.

Negrete maneuvered the shadow truck onto the 22 Freeway after rush-hour – sweeper crews typically don't start before 9 a.m. so they don't make congestion worse. From his elevated cab, he could see motorists staring at their phones or putting on makeup.

Leading the slow-moving Caltrans caravan were trash trucks, with workers jumping in and out to pick up large refuse that would damage the sweeper. Next was the sweeper truck itself. Bringing up the rear were two shadow vehicles, the latter driven by Negrete, with a California Highway Patrol unit between them.

His job is to block havoc.

Negrete, who has driven a shadow truck for most of his 13 years with Caltrans, has never been hit in a shadow vehicle. But he has had plenty of close calls. Recently, a driver spun out and went over the side of the roadway into ice plants, narrowly missing the street sweeper. "I leave everything in the hands of God," Negrete said. "I pray a lot, before I do anything. It bothered me more when I first started, because I was thinking, 'What did I get myself into.' "

The busier the freeway, the higher the danger.

Cesar Vazquez, a Los Angeles-based lead maintenance worker, learned that several years ago when he moved from crews covering Pomona and Rosemead to one covering parts of the 710, the 60 and the 10 freeways. "They train you for this stuff, but you have to be on your toes to make a decision," Vazquez said. "Not just a decision for you, but (for) the guys in front and behind you. And if we get nailed, someone in the traveling public will as well.

"It's nerve-wracking. The bad part is you have to get in there the next day and do it again," Vazquez added. "You are constantly looking back, 'Is it going to come, is it going to come?' " Vazquez has been sideswiped twice by diesel trucks, neither of which stopped. Oftentimes, Vazques said, passing vehicles miss his convoy by inches.

Caltrans workers often find themselves the targets of middle fingers, harsh words and sometimes even bottles and, at least once, a sandwich. "The biggest misconception is we make people late to work," Vazquez said. "If we weren't there to sweep those freeways, you wouldn't be getting to work, the amount of debris and amount of trash that accumulates. But people seem to say, 'Oh well, Caltrans made me late again.' "

This article first appeared in the Mercury News. If you have ideas about other actions or equipment you suggest to enhance the safety of sweepers during operation, please let us know so we can add your info as an addendum to this article.

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