To keep local roadways in good condition for the traveling public, Iowa county engineers monitor pavement conditions and analyze a wealth of pavement data to predict when and where maintenance will be needed. Now, a new tool developed through a research project for the Iowa Highway Research Board will help streamline this complex process.  

Developed through extensive analysis of past pavement performance data from Iowa roadways, the Iowa Pavement Analysis Techniques (IPAT) tool will help engineers accurately and efficiently estimate the remaining service life (RSL) of individual pavement sections or roadway networks. Armed with reliable RSL estimates, engineers can plan and prioritize maintenance treatments and rehabilitation projects to make the best use of limited county funds. The IPAT tool will be implemented across the state in the coming months. 

Learn more about this project in Iowa DOT’s new research brief and final report. 

Traditional chloride- and acetate-based deicers are widely used in maintenance operations to clear snow and ice from roadways.  

These deicers are cost-effective, but they can damage concrete and steel and have adverse effects on soil and aquatic ecosystems. 

While not yet widely available, agro-based deicers formulated using corn extracts offer a potential deicing solution that is effective for snow and ice removal and less harmful to infrastructure and the environment.  

Researchers tested a series of corn-based deicer blends to find the combinations that exhibited enhanced freezing-point depression, minimized corrosion, and melted ice at low temperatures. 

The top-performing deicers used different mixes of salt brine and three different types of corn-derived alcohols. 

While cost and logistics issues must be explored further, this research demonstrates that corn-based deicers, in terms of performance, may be viable for road maintenance use. 

Learn more about this project in Iowa DOT’s new research brief and the investigators’ technical brief and final report. 

Each year, spring’s warmer weather can be a welcome change after months of winter. However, the rain and melting snow that accompany the higher temperatures can also pose a seasonal flood risk for some areas in Iowa.   

Flood damage to roads, bridges or other infrastructure is often easy to see; however, other adverse effects, such as road closures that limit mobility or detours that require longer travel times, are less visible and harder to gauge. 

To gain a more complete understanding of a flood’s impact and how the state’s finite resources should be allocated for maximum benefit, Iowa DOT Research partnered with researchers from Iowa State University on two research projects that concluded in 2021: 
 

• Asset Management, Extreme Weather and Proxy Indicators. Studying flood-prone areas in Iowa, researchers used simulations to identify the roads and bridges most at risk of flood-related closures, as well as the structures that serve the most traffic and keep communities connected.
• Assessing and Enhancing the Transportation Resilience for the State of Iowa. This study evaluated how well transportation systems in Iowa will be able to adapt and recover after a major flood event.

Together, these two projects provide a more holistic view of all the potential effects a flood could have on a community and which structures might be most vulnerable. Leveraging the information, Iowa DOT is better equipped to prepare for the next flood and prioritize the state’s resources where they’re most needed.

When earth is moved during construction, it can more easily wash away to areas it doesn’t belong and adversely affect farmland and wildlife.

Not only is erosion a problem for the environment, but minimizing its negative effects is the law—Iowa state and federal laws require erosion and sediment control (E&SC) measures to protect the delicate natural balance.
 
Iowa DOT has a variety of time-tested E&SC practices in place, but it wasn’t clear whether these were the most effective or whether there were other approaches that could be undertaken to achieve better or cheaper results.

Over two construction seasons, researchers studied a range of E&SC methods and determined which worked best and what needed improvement.
 
Highlights of the findings include cost-effective new techniques for building wattles (low-lying barrier rolls, pictured) and fabric fences to maximize stability and erosion control.

Research also showed that water retention ponds might not be as effective as had been previously thought, leading to important new areas of inquiry.
 
Look for new E&SC specifications in 2021.

Other findings and greater details are available in Iowa DOT's new research brief, as well as the investigators’ final report and technology transfer summary.

It feels like spring at Iowa DOT Research! This new season is nearly here, bringing an exciting time of growth and change. March 1 marks the start of our new research cycle as well! 

You may have the next great transportation-related idea; submit it now to give it the best chance to grow into a fully developed proposal!  
 
Submitting an idea at the start of the new research cycle means it will have the most time in the discussion and evaluation phase – a critical step toward helping it succeed. 
 
With more feedback and engagement, ideas become better, making them more likely to be selected for further development.  
 
Don’t have a submission of your own? No problem! You can help others improve their ideas by voting or adding your comments. Feedback for the spring cycle will remain open until July 25, 2021.  

Our annual research calendar shows how the whole process works throughout the year, and our Ideas site is the place to learn more and get involved. Check it out and see what ideas are growing at Iowa DOT Research!

Concrete is a common construction material for many Iowa bridges. The use of conventional concrete in bridge components, however, requires periodic maintenance and repair to address damage caused by heavy traffic loads, weather, and chloride deicers. But closing bridges to repair or replace damaged concrete creates hardships for drivers across the state.  

Ultra-high performance concrete (UHPC) has the potential to significantly reduce these issues. UHPC is much stronger and more durable than conventional concrete, meaning repairs are needed less often. But due to its proprietary nature, UHPC has historically been cost-prohibitive for many bridge applications.  

A recent Iowa DOT research project could change that. Researchers at Iowa State University developed a set of nonproprietary UHPC mixtures using readily accessible—and more affordable—materials. Testing indicated that the nonproprietary mixtures’ strength and durability were comparable to proprietary mixtures and at one-third of the cost, offering a promising alternative for Iowa bridge structures.  

Learn more about this project in Iowa DOT’s new research brief and the investigators’ final report and technical brief.  

International Walk to School Month, held each year throughout the month of October, highlights the importance of safe and pedestrian-friendly communities all over the world.  

Improving safety and mobility for pedestrians – and all road users – are key to our mission at Iowa DOT Research. Recently we’ve invested in research to investigate how self-heating pavements can be installed at crosswalks and bus loading areas to melt ice and make walkways safer. In addition, our ongoing work with the Fostering Innovation in Pedestrian and Bicycle Transportation Pooled Fund Study has helped us develop and implement a variety of innovations that benefit non-motorists across the state. 

Learn more about Iowa DOT’s efforts to make our state more safe for pedestrians, and submit your research ideas to help us understand the transportation issues important to you. Our summer research cycle will be accepting ideas until October 31! 

Iowa DOT relies on applied research to solve the state’s most pressing problems and to identify, test, and pilot new products and process improvements. 

But with so many transportation-related avenues of inquiry, it is difficult and cost-prohibitive to explore every possibility.  

Pooled funds offer a smart solution: By working with other state departments of transportation (DOTs) interested in doing the same research, Iowa DOT can share the cost of a project—sometimes in the hundreds of thousands of dollars—without sacrificing any quality. 

Every participating agency can achieve the same results at a fraction of the cost and influence the direction and scope of the research. 

This means Iowa DOT is able to invest in more projects per year, getting significantly more value and insight from its research budget. 

Iowa DOT serves as lead agency for more pooled funds than any other state DOT in the nation, positioning Iowa as a nationally recognized leader in transportation-related research and bringing new and exciting innovations to Iowans in every part of the state. 

Learn more about Iowa DOT’s pooled funds.

Traditionally designed roads and bridges can easily withstand the occasional flood. But as storms that used to happen once every 100 years become more frequent and extreme, Iowa DOT must ensure its infrastructure is ready. 

To determine how much water future storms may bring and how often flooding may occur, researchers studied historic flood events and used the data to develop a new online resource – the Iowa Flood Frequency and Projections Tool – that anyone can use.  

In addition to updating its building standards, Iowa DOT is already using this project’s findings to redesign segments along two major highway corridors in the state. 

Learn more about this project in Iowa DOT’s new research brief, and check out other Iowa DOT research efforts on the News & Publications page. 

Traditionally, the criteria used for testing concrete mixtures are largely based on material strength and air content. But verifying that pavements are sustainable and long-lasting depends on other engineering properties. Iowa DOT led a multistate, multiyear effort to deploy new technologies that ensure high-quality pavements that require less maintenance over time. 

This research project involved comprehensive educational initiatives, pilot testing, and project support. As a result of this effort, Iowa DOT and 18 other states have improved concrete mix specifications and are using new performance-based testing technologies to deliver improved concrete pavements. 

Iowa DOT is also leading a follow-up project focused on handling concrete mixes at the construction site.  

This research gives agencies new and better tools to select effective performance-based specifications for pavements and overlays that perform well throughout their design life cycles.  

Learn more about this project in Iowa DOT’s new research brief, and check out other Iowa DOT research efforts on the News & Publications page. 

We all know seat belts save lives, but have you ever considered that they can save money as well? 

Costs for hospital stays and physical rehabilitation after a crash can quickly add up. 

Ahead of Child Passenger Safety Week and National Seat Belt Day, which will be held this year from September 15-21 and on November 14 respectively, a new Iowa DOT Research project aims to provide more insight into the financial benefits of wearing a seat belt.  

By reviewing and analyzing the vehicle crashes that occurred in Iowa between 2012 and 2016, researchers will consider a variety of crash characteristics, including the extent of the occupants’ injuries and whether seat belts were used.  

With a greater understanding of the safety – and financial – benefits seat belts provide, experts hope to be able to convince drivers and passengers to make sure their seatbelts are fastened every time they drive or ride in a vehicle.  

Learn more about this and other projects Iowa DOT Research is funding on the Ideas site. 

Iowa’s unpaved roads are essential for keeping rural communities connected and agricultural products moving. National Farm Safety and Health Week – which will take place this year from September 18-24 – is the perfect time to highlight Iowa DOT Research’s efforts to increase the roads’ safety and durability. 

These roads are designed to have a thick aggregate top layer, but heavy equipment and extreme temperature fluctuations can break down the materials on the surface and cause potholes and other distresses to form prematurely.  

Engineers have long known that keeping the aggregates in place is key to longer-lasting roads, but finding a solution that’s both economical and environmentally friendly hasn’t been easy. 

Quarry fines—the small particles left after larger rocks and materials are removed from a quarry—are both cheap and plentiful.  

To learn whether adding these fines to the aggregates on a road’s surface would help the road last longer, researchers evaluated various fines and aggregates in the laboratory to find types that interlock well together and identify the ideal proportions of each for a successful mixture. The researchers then constructed seven test sections on unpaved roadways that experience heavy equipment traffic, using fines from five quarries across the state. Through a variety of durability tests and comparisons with two control sections, the team evaluated the fines’ impact on the performance of each section over several seasonal freeze-thaw cycles.  

The efforts showed that while all five types of fines worked well to keep the surface aggregates in place, local road managers will need to carefully consider a number of factors, including the costs to buy the materials and haul them to the jobsite, to determine if adding waste quarry fines makes sense for a specific project. 

Learn more about this project in the new research brief from Iowa DOT. 

Iowa DOT’s engineers have long recognized the link between the quality of a pavement’s foundation and the long-term durability of the finished road. But despite improvements in how foundations are designed and the types of materials that are used, there is sometimes still a gap between how the road is intended to be constructed and what is actually built.  

Advancements in technology now make it possible to directly measure and analyze a pavement’s foundation during the construction process to ensure it has been compacted sufficiently and uniformly. This gives inspectors the tools to pinpoint any weaknesses in real-time so they can be addressed while construction is still underway.  

With a grant from the federal Accelerated Innovation Deployment (AID) Demonstration program, Iowa DOT and a team of engineers recently piloted new tools and methods to assess the foundations at five road construction projects across the state. The efforts helped the team better understand what measurements should be taken, how the equipment should be used and calibrated, and how the data should be interpreted.  

The project’s results will help Iowa DOT and other transportation agencies across the country save significant resources as better foundations lead to longer-lasting pavements with fewer maintenance needs.  

Learn more about this project in Iowa DOT’s new research brief.

When animals attempt to cross a roadway, the results can be hazardous for everyone. In Iowa, crashes between vehicles and large wildlife like deer can pose a serious threat. But dangers also exist when vehicles swerve to avoid an animal in the road, or when drivers stop to help an animal across.

Even lesser known are the risks for smaller animal species like reptiles and amphibians. For these populations, roads that bisect a natural habitat can inhibit migration and affect animals' habits during mating season.  

World Animal Road Accident Awareness Day – this year on October 10 – serves as an annual reminder of the importance of keeping animals off roadways, for the health and safety of humans and animals alike.  

Since 2017, Iowa DOT Research has partnered with other transportation agencies in the United States and Canada on the Wildlife Vehicle Collision Reduction and Habitat Connectivity Pooled Fund. Together, the group works to identify potential solutions for keeping animals off roadways without restricting safe passage – such as tunnels, fences, and noisemakers – as well as strategic messaging that can effectively increase driver awareness.  

By sharing the costs of research, each agency can benefit from the findings with less financial investment than they would spend on their own.   

Learn more about Iowa DOT Research’s commitment to safety for all road users on the Ideas site. 

Every Iowa DOT research project relies on a team of individuals to represent different perspectives and priorities during every stage of development. 

While every team is different, there are four key roles on every project’s team that help take the research from idea to final completion. These are: 

The Project Champion who assembles the stakeholders and subject matter experts, and who will provide valuable input as the project’s scope and goals are developed. 

Members of the Project Development Group who determine the purpose and objectives of the project at the outset, and who evaluate the project’s final results to ensure success. 

The Technical Advisory Committee which consists of experts and representatives from the federal and municipal governments to lend support and assistance as needed. 

The Research Liaison who provides administrative and oversight support throughout the project. 

When your expertise is needed, we hope you’ll jump at the chance to contribute to transportation research in our state.

County engineers are charged with maintaining thousands of bridges on Iowa’s secondary road system. In bridges built with T-shaped concrete beams, individual beams are typically connected with longitudinal joints. These joints are vulnerable to environmental and mechanical stresses, leading to frequent maintenance and repair needs. 

New materials offer promising alternatives for these longitudinal joints, not only improving the strength and durability of individual joints but also increasing the service life of the entire bridge structure. Focusing on short-span bridges, researchers developed and tested a new design with an ultra-high-performance concrete longitudinal joint and reinforcing bars made of corrosion-resistant, high-strength steel. They found significant potential for stronger and longer-lasting bridges. 

This new bridge system will likely offer significant cost savings in the long run. The next steps for Iowa bridge engineers are to explore construction considerations in the field and evaluate the performance of this innovative bridge system in real life. 

Learn more about this project in Iowa DOT’s new research brief. 

World Bicycle Day, held each year on June 3, celebrates the many health and environmental benefits that bicycling can offer.

As the number of Iowa’s bicyclists continues to grow each year, research can help identify infrastructure improvements to make riding safer and more enjoyable for everyone. 

But research can be expensive. To find cutting-edge yet affordable solutions that enhance the bicycling experience while increasing safety, Iowa DOT collaborates with 13 other states through the Fostering Innovation in Pedestrian and Bicycle Transportation Pooled Fund Study.  By sharing the costs of research, each state stands to benefit from the findings with less financial investment than they would incur individually.  

Learn more about Iowa DOT Research’s commitment to non-motorized transportation on the Ideas site. 

Iowa DOT’s role as a world leader in advancing transportation research is possible thanks to its many partnerships with a variety of experts.

These relationships—with university researchers, technical authorities, industry professionals and others—have been key in helping the Iowa DOT drive improvements to transportation systems across the globe. 

One partnership stands apart for its longevity and success: For the past 24 years the Iowa DOT has collaborated with the Institute for Transportation at Iowa State University, or InTrans, for research assistance, technical support, asset management and more. 

With an annual average of 160 active research projects for Iowa DOT, highlights include:
 

• Design and Performance Verification of a Bridge Column/Footing/Pile System for Accelerated Bridge Construction, led by InTrans principal investigator Sri Sritharan.
   
• Development of Granular Roads Asset Management System, led by Bora Cetin.
   
• Iowa DOT Office of Maintenance Snowplow Optimization, led by Jing Dong. 

InTrans’ commitment to improving transportation efficiency, safety and reliability makes for an ideal partner.

And with laboratories and testing facilities dedicated to pioneering research in methods, materials and technologies, InTrans is well positioned to help the Iowa DOT accomplish its own similar goals for the future.

Iowa DOT is committed to advancing transportation research, but it can’t do it alone

Since 2003, Iowa DOT has partnered with the University of Iowa for help in achieving its research goals.  

Specializing in a variety of transportation issues such as hydraulics, public health, virtual reality and advanced computing, connected and autonomous vehicles, and driver behavior, the University of Iowa has provided research assistance and technical support on more than 40 Iowa DOT research projects. Some of these include: 

• Development of Self-Cleaning Culverts, led by principal investigator Marian Muste. 
• Traumahawk: Improving Treatment for Crash Victims Using Photos and a Smartphone App, led by Daniel McGehee.
• Passenger Restriction Waiver Impact on Young Driver Crash Rates, led by Michelle L. Reyes.

With each collaboration, Iowa DOT gains insight into the cutting-edge innovations and strategies that can be implemented to enhance the safety and mobility of Iowa’s traveling public.  

Thanks to its relationship with the University of Iowa – as well as other university researchers, technical authorities and other industry professionals – Iowa DOT Research has earned a reputation around the world as a leader in transportation research.

The Iowa Transportation Program Management System (TPMS) has been in use since 2001, allowing cities and counties across the state to manage construction projects using a shared system that all stakeholders can access.  

The system contains details on thousands of active and completed projects and is designed to allow users from Iowa’s cities and counties, as well as those from state and federal transportation authorities and private businesses, to work together on shared projects. But after roughly 20 years, as technology has vastly improved and the way people work has evolved, it was clear the system needed an overhaul.  

To create a modern program that works for everyone involved, a team from the Iowa County Engineers Association Service Bureau (ICEASB), which maintains the TPMS, crisscrossed the state over several years to consult with thousands of users. With input collected from designers, contractors, builders, project managers, and others, the ICEASB unveiled TPMS 2020 in July 2021. 

New and improved features include real-time updates to ensure data is current, greater security against modern threats, additional automation of routine tasks, a more user-friendly interface, and a modular framework to make future updates easier.

Learn more about this project in Iowa DOT’s new research brief and final report.