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Kelly Senger
Illinois Department of Transportation
Central Bureau of Materials
Low Carbon Transportation Materials Program
IDOT is taking additional steps to reduce the environmental impact of our projects by using low-carbon transportation materials (LCTM). This effort focuses on selecting construction materials and products that emit fewer greenhouse gas (GHG) emissions during manufacturing and construction.
As part of this program, IDOT will begin using environmental product declarations (EPDs) to better understand and compare the environmental impacts of construction products. These approaches will be introduced and tested during the 2027 construction season and become a requirement by 2029.
This page will share information about the program, how it will be implemented, and how industry partners and stakeholders can get involved.
Program Goal
- Consider environmental impact alongside cost and performance when selecting materials for IDOT projects.
Program Objectives
- Define what "low-carbon" means for commonly used construction materials.
- Work with industry to expand the availability of EPDs for materials like concrete and asphalt.
- Build a practical, long-term approach for using low-carbon materials in transportation projects.
Timeline
IDOT will ask Illinois concrete, asphalt, and steel producers from across the state to develop and submit EPDs to support the GWP benchmarking process. IDOT is currently developing a financial incentive for participants and will provide more information when the incentive program is finalized.
Developing global warming potential (GWP) benchmarks for construction materials and products such as concrete, asphalt, and steel requires quality data that comes from environmental product declarations (EPDs.) IDOT will first ask Illinois concrete and asphalt producers to develop and submit EPDs to support the GWP benchmarking process. EPD collection for GWP benchmarking will happen outside of the normal construction process. All asphalt and concrete producers who supply to Illinois are asked to participate. Details will be released when the incentive program is finalized.
Once a representative amount of EPDs is collected, the program will identify regional and product type environmental global warming potential (GWP) benchmarks.
Starting in 2027, IDOT will select projects to pilot EPD collection in construction. Within the year, IDOT will pilot embodied carbon as one of the attributes to consider in construction, along with performance, cost, and other factors. Starting in 2028, this will be put into conventional practice, and final program refinement will be implemented for full rollout in the 2029 construction season, ensuring all IDOT’s projects are safe, durable, and low carbon.
IDOT will offer training opportunities to support construction professionals, suppliers, and engineers in understanding and implementing the low-carbon transportation materials (LCTMs) program. These sessions will provide practical guidance on submitting environmental product declarations (EPDs) to the global warming potential (GWP) benchmarking program and strategies to reduce embodied carbon in transportation projects.
Through these training opportunities, participants will gain the knowledge and tools needed to adopt sustainable construction techniques, stay ahead of industry standards, and contribute to Illinois’ efforts to build greener, more sustainable infrastructure.
This FAQ outlines the plan for how the LCTM program will operate. As IDOT continues to develop the program in collaboration with partners and stakeholders, elements may be refined.
What is the LCTM Program?
Illinois’ Low Carbon Transportation Material (LCTM) program is a state initiative that encourages the use of construction materials with lower greenhouse gas (GHG) emissions in transportation projects. The program focuses on commonly used materials such as ready mix concrete, asphalt mixtures, and steel products, and uses environmental product declarations (EPDs) to identify and support lower-carbon options.
Goals of the program are:
- Increase the use of LCTMs in IDOT projects
- Facilitate the use of LCTMs without sacrificing quality/performance
- Use environmental product declarations (EPDs) to define low-carbon
- Provide technology transfer and workforce development
Who is Involved?
IDOT is partnered with academia, consultants, and state and national industry associations to design and implement the program, including the following.
What materials will be considered?
Ready mix concrete, asphalt mixtures, and steel products (structural steel shapes and rebar).
What is a low-carbon transportation material?
A low-carbon transportation material is a construction material or product that has lower greenhouse gas (GHG) emissions than similar materials serving the same purpose. These emissions, known as embodied carbon and measured by their global warming potential (GWP), come from activities such as raw material extraction, manufacturing, and transportation.
One method of defining “low-carbon,” is the US EPA’s Interim Determination on LCM, which considers materials low-carbon if their GWP ranks among the lowest among similar products meeting the same functional requirement. They defined this as materials that fall within the lowest 20th percentile of GWP for their category. If products in the 20th percentile aren’t available, products that are in the lowest 40% may be used.
Are low-carbon materials comparable in quality to conventional materials?
The performance of low-carbon materials is often indistinguishable from that of conventional materials. Low-carbon refers to how the product is produced, and does not indicate a reduction in strength, durability, or functionality. Performance will not be compromised for LCTM. Low carbon versions of like materials may be achieved through:
- Using alternative raw materials, or supplementary ingredients (replacing a high-carbon product in a supply chain with a lower-carbon product that supplies the same performance)
- Improving manufacturing efficiency
- Switching to lower-emission energy sources for production
Why do embodied carbon emissions matter?
Embodied carbon emissions make up a significant share of global greenhouse gas (GHG) emissions. About 11% of global emissions come from the production of construction materials for new buildings and infrastructure. In the US, public projects account for a large portion of this impact, with an estimated 32% of construction-related embodied carbon emissions coming from government-funded work.
By considering embodied carbon in material selection, IDOT can use its purchasing power to help reduce emissions and support the growth of lower-carbon construction materials and products, while still requiring that products meet the same performance requirements.
What is GWP benchmarking? / How will the GWP targets be set?
IDOT will collect and analyze environmental product declarations (EPDs) from previously used IDOT materials and products to establish Illinois-specific global warming potential (GWP) benchmarks by material/product and sub-category. This process is referred to as GWP benchmarking, and it looks at the range of emissions reported for similar materials used across the state.
All data collected for benchmarking will be handled confidentially. Individual company data will not be shared publicly and will only be used in aggregate to develop benchmarks.
Based on this data, IDOT will set GWP targets that reflect typical industry performance. Products with GWP values at or below these targets will be considered low-carbon options.
Why should I participate in the GWP benchmarking?
Participating in GWP benchmarking helps shape how “low-carbon” materials are defined in Illinois. By contributing environmental product declarations (EPDs) from previously utilized IDOT materials and products, you ensure that benchmarks reflect real-world industry practices and regional conditions.
Facilities at all stages (whether or not they have taken steps to reduce carbon emissions) are encouraged to participate. Broad participation helps create fair, accurate benchmarks and supports a more effective program for everyone. Financial incentives are available for those who participate.
Why use EPDs?
Environmental product declarations (EPDs) provide a consistent and transparent way to understand the environmental impacts of construction materials and are developed in accordance with global consensus standards. They report data, such as global warming potential (GWP), using a standardized method called life cycle assessment (LCA), which assesses impacts from raw material extraction through manufacturing and transportation.
EPDs follow established rules for specific product types and are third-party verified, helping ensure that information is reliable and comparable across similar materials. This makes EPDs useful for making more informed product selection decisions and reducing embodied carbon in construction projects.
EPDs are widely supported by industry organizations such as the American Institute of Steel Construction (AISC), National Ready-Mixed Concrete Association (NRMCA), and the National Asphalt Pavement Association (NAPA). EPDs are already being used by transportation agencies and private entities across the country. IDOT will use EPD data to develop Illinois-specific GWP benchmarks and support the transition to lower-carbon materials.
When will I have to provide an EPD?
IDOT anticipates requiring environmental product declarations (EPDs) for construction projects beginning in 2029. Leading up to this requirement, the Department will phase in EPD use to allow industry time to prepare.
- 2026: Collect EPD data to establish baseline global warming potential (GWP) benchmarks
- 2027: Pilot the use of EPDs on select construction projects
- 2029: Require EPDs for applicable materials on applicable projects
These phased steps are intended to support a smooth transition and give manufacturers and contractors time to develop and submit EPDs.
Who does the LCTM apply to?
The program primarily applies to those providing commonly used materials such as ready mix concrete, asphalt mixtures, and steel. Concrete and asphalt plants and contractors should be aware of the pending requirements through their local industry association and IDOT communication.
As information is gathered on local product EPDs (2026) and pilot project work (2027), requirements will vary by project and material. Over time, more participants in the supply chain may be asked to provide environmental product declarations (EPDs) to help demonstrate that a product meets a specific GWP threshold.
How will the program change construction going forward?
IDOT’s existing specifications already allow the use of lower-carbon transportation materials (LCTMs), but these opportunities have historically been underutilized. The program will explore and promote the use of tools and practices already available within IDOT’s existing framework that have not yet been fully leveraged to advance sustainability goals.
IDOT will include product GWP in construction considerations along with performance, cost, etc. This process will not only help us select the right performing products, but also products that are as environmentally friendly as possible. The innovative concepts utilized by suppliers and contractors derived through the LCTM program will help build new knowledge in the workforce and prepare all sectors involved for a new way of doing both private and public construction.
How does the program help my business?
Gain a competitive edge: As public Buy Clean policies and private-sector low-carbon requirements become common, providing environmental product declarations (EPDs) can open new markets and make your products more viable in more areas. By participating in IDOT’s global warming potential (GWP) benchmarking program, your products help define Illinois’ baseline for low-carbon construction and shape state benchmarks. Potential performance benefits: According to the Federal Highway Administration, LCTM-compliant materials may offer longer paving windows and increased durability. By using the information from the underlying life cycle assessment, you could gain a greater understanding of your supply chain and improve product performance.
Operational savings: Improving LCTM metrics could help producers lower utility costs and improve overall efficiency.
Do other states have similar programs?
Several states have policies and programs that require EPDs and set GWP limits for key construction materials and products, especially concrete and steel. Five states are developing LCTM programs, while others have enacted Buy Clean and embodied carbon policies for building and infrastructure projects. States include California, Colorado, Kentucky, New Jersey, New York, Maryland, Massachusetts, Minnesota, Oregon, Washington, and Wisconsin.
Who can I go to with questions?
See the contact at the bottom of the page.
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