Can you hear me now?

Paint train really close upYou would think that a huge orange truck, or multiple huge orange trucks, with bright lights flashing would be enough to catch a driver’s attention. For drivers who are paying attention and devoting their energy to the task of driving, seeing the trucks and lights is more than enough to warn them that something’s going on ahead. But we’ve all seen those drivers who are paying more attention to their dinner, phone, or passengers than to the road. And that is dangerous for all of us.

We do everything we can to get people to pay attention to protect our own people and those who share the road with us. Many of the operations we perform on the road require the use of more than one truck. An attenuator is always the last vehicle in the chain that is placed between workers on the road (such as a paint crew) and the flow of traffic. Its job is to warn other vehicles of the work that is being performed as well as serve as a buffer to protect workers from traffic. We are testing a new tool this year called an audible warning system that is attached to an attenuator.


Wrecked attenuatorLast year the Iowa Department of Transportation had nine pull-behind impact attenuators hit. Luckily, the attenuators did their job and protected the crews working ahead of them, but while safety is always our main concern, there is also a monetary cost to these crashes. Replacement cost for each attenuator is $14,000. If the lighted arrow board attached to the attenuator is also damaged, that adds another $2,300 to the replacement cost. In addition to the monetary costs, the loss of use of these pieces of equipment can delay work we need to do and cause you delays in where you need to go.

 “Because we work so closely with other states on equipment, we’re able to share ideas and new technologies,” said Ken Morrow from the Office of Maintenance. “A few years ago, we went down to Saint Louis to see an audible system they were using to protect workers on their paint crew. The system uses much brighter flashing lights and emits a unique sound geared towards getting driver’s attention. It took a while to work everything out, but this summer we’re testing two systems on our paint crews in central and eastern Iowa and will be adding eight more systems all over the state later this summer.”

The system isn’t perfect, but it’s a step in the right direction. Currently, the audible system the Iowa DOT is using relies on the operator in the truck to activate it. Morrow said, “In the future, we are hoping that the system can be automated so that it senses when a vehicle is approaching too quickly or getting too close. But for now, our operator watches traffic and turns on the system when there is a vehicle that isn’t maneuvering around the maintenance operation. For the most part, the audible sound and increased lights seem to get the distracted driver’s attention. We haven’t had any vehicles hit with the audible system in place.”

Morrow said the two current audible systems are being used on mainline paint crew trucks. Each system costs $9,000. “When we get the remaining 10 systems, there will be one for each of our six mainline paint crews. It will be up to district management to determine where to position the remaining audible attenuators.”

Paint train closer up - attenuator lit

Keeping you safely traveling down Iowa’s highways is our main goal. Audible attenuators are just another step in what we are doing to hit this goal. But we can’t do it alone. Help us, help you by paying attention and using all your senses to navigate through work zones whether they are stationary or mobile.

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