New technologies make Iowa work zones safer

IMG_0792Last year, 13 people died in crashes in Iowa road work zones. In every crash, there is usually more than one specific cause, but nearly 94 percent of all fatal crashes can be attributed to one or more actions taken by the driver.

To reduce the number of work zone crashes and fatalities and improve traffic flow, four years ago the Iowa Department of Transportation began a Traffic Critical Projects program Part of that program includes deploying a number of “intelligent” work zone safety features on construction projects in areas with high traffic volumes. Those efforts will be continued and enhanced this summer with the deployment of intelligent work zone features on about 30 of the more than 500 work zones anticipated on state-managed highways this year.

Tim Simodynes, the Iowa DOT’s intelligent transportation systems engineer, said, “Over the years the Iowa DOT has installed a number of permanent dynamic message signs, cameras, and traffic sensors used by our Traffic Management Center in Ankeny to monitor traffic and manage traffic incidents along the state-managed system of interstates and state and U.S. numbered highways. You may have seen the signs in the Des Moines area alerting you about travel times to upcoming exits. All of these permanent signs and sensors have benefits, but they are limited to the area where they are installed.”

One of the most visible safety features in intelligent work zones is the automated queue detection and warning systems. The queue detection systems can use any combination of permanent or portable traffic sensor data to automatically post warning messages to either permanent or portable dynamic message signs. “With our queue detection systems, the sensors detect slow traffic speeds and then automatically post messages to the signs letting motorists know if there is slow or stopped traffic ahead,” said Simodynes. “And the temporary devices, permanent devices, and alerts are all tied together through the Traffic Management Center.”

Signs on 511
Sign messages are not only visible to motorists, anyone can view them on

The Iowa DOT’s statewide intelligent work zone contract allows them to expand those same technologies to work zones with portable versions of the permanent signs, cameras, and sensors. “The cameras and sensors allow the to monitor traffic and incidents in our work zones. They can use the signs to post message for drivers,” said Simodynes. “Sign messages, photos and live video from the cameras can also be seen by the public at”

 “Our focus on work zone safety has been constant, but our mindset regarding traffic flow during construction has been changing over the past few years to thinking more about the impact to traffic for each project. In the past we worked hard to produce the best product in a quick and efficient manner, and that would sometimes include heavy impacts to traffic with significant backups. With the tools we have available, we can still have safe and efficient projects, but do a better job of keeping traffic flowing through our work zones.”

Iowa DOT's Traffic Management Center
Operators at the Iowa DOT's Traffic Management Center can monitor images from both permanent and temporary cameras on Iowa's roadways.

Simodynes said, “Iowa DOT’s statewide approach to intelligent work zones is unique. Many states deploy various types of intelligent work zone technologies on a project-by-project basis, but their systems may not be compatible across projects and their traffic management centers may not be able to monitor them. In our case, the Traffic Management Center receives alerts when queues are detected and uses the cameras and dynamic message signs just like our permanent cameras and signs. And they are also able to let us know whenever equipment or a work zone may need attention.”   

The statewide approach also offers a lot of flexibility. “During the construction season, we are able to add or remove signs, cameras, or sensors on individual projects, and even add entirely new projects within just a few days,” said Simodynes. “We even deploy sensors in certain locations to collect detailed traffic data that will be used to determine when lane closures will be allowed for a project that may not start for a year or more. This detailed traffic data helps us maximize the time we allow contractors to close lanes for work, while minimizing the impact to traffic.”

Iowa’s approach to intelligent work zones is getting a lot of attention around the country. Simodynes said, “We do a lot of presentations and get a lot of requests from other states for information about what we are doing and how it all fits together.”

Work zone temp camera
Combining portable cameras, message and arrow boards and traffic sensors allows motorist to get advanced warning in the event an issue comes up in a work zone.

While the updated technology may help improve safety and traffic flow through work zones, Simodynes and the Iowa DOT team isn’t stopping there. He said, “Whenever a lane is closed on a mulitilane roadway, an illuminated arrow board is used to notify drivers which lane is closed. So we are partnering with several other states to add sensors to our arrow boards that will send their location and status back to the Traffic Management Center. That way we can track exactly when and where lanes are being closed and reopened to better monitor our construction projects. This information can also potentially be shared on 511 to let people know in real time where lane closures are happening.”

The Iowa DOT is also working with the Institute for Transportation at Iowa State University on an alert system to notify key Iowa DOT personnel in real time when traffic backups are occurring. Simodynes said, “We are using all this technology to work smarter. With more work being done every year, but fewer employees available to be on a job site, the technology can provide the eyes and ears we need to maintain and improve safety.”

Safety for Farmers to and from the field,
They provide your food - Please Yield!!!
Thanks Tim for saving lives!

Orange you glad you slowed down? - love the humor for important topics. Thanks.

Congrats Tim on a well researched and implemented plan.

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