Transportation Research under One Umbrella…
Transportation research at Illinois has historically spanned multiple disciplines, such as computer and information sciences, engineering, geosciences, and life, physical, and social sciences. Each of those branches of knowledge have accomplished distinctive research advances over the years. However, all such scientific investigation has been done so far under the banner of a singular field of study, which led the College of Engineering at the University of Illinois at Urbana-Champaign (UIUC) to announce the Smart Transportation Infrastructure Imitative (STII)—to harmonize all transportation research under one umbrella.
STII is envisioned “to improve safety, mobility, security, and connectivity and reduce energy, consumption, and emissions for the next paradigm of transportation systems, including roadway, air, rail, water and intermodal.” Two main focus areas for this initiative are the development of research and policy in support of safe and automated mobility of people and goods and the fulfillment of national and global connectivity needs.
Professor Imad Al-Qadi, director of the Illinois Center for Transportation and the Advanced Transportation Research Engineering Lab, has been appointed director of the Initiative.
“Advances in computing, robotics, and artificial intelligence have enabled revolutionary technologies such as autonomous and connected vehicles to emerge, and these next-generation systems hold the promise to completely change the paradigm of transportation efficiency, sustainability, resilience, and safety,” Al-Qadi said.
On the level of system operations, next-generation transportation systems aim to influence or replace human behavior and to enable coordinated strategies that improve system performance on key multimodal transportation links and intersections. On the other hand, on the infrastructure level, implementation of next-generation transportation technologies will mandate principles and guidelines for the design, maintenance, and rehabilitation of future physical assets such as sustainable infrastructure materials capable of directly communicating and interacting with vehicles and other types of urban infrastructure facilities. As such, the need for all-embracing research in the technology, engineering, planning, regulatory, policy, legal, and social spheres of next-generation transportation systemsbecomes obvious.
Research is needed on new technologies and innovations that extend beyond the immediate scope of vehicle and transportation infrastructure systems, well into machine-and-human system integration at the microscopic level and network-level control and coordination at the macroscopic level; security and fault tolerance; verification and validation (V&V) of new methodologies; and the flow and infrastructure performance implications of autonomous and connected vehicles.
Even though air, rail, and water transportation have registered major advances in recent years, the challenges that are yet to be overcome are numerous. For instance, the benefits of connected and autonomous vehicles can only be realized if and when technology innovators, vehicle manufactures, and infrastructure planners change current practices and strategically prepare for the next-generation transportation systems. Also, there is the need for government agencies to adopt new regulatory policies and laws that would enable the assimilation of emerging vehicle technologies and operation concepts into our multimodal transportation network.Connected and autonomous mobility entails multiple levels of intra- and inter-agency coordination and process redesign that pose an additional challenge.
In its first grassroots meeting held December 18, 2017 to kick-off the discussion about a strategic action plan for achieving STII’s vision, more than a hundred department heads, unit directors, and faculty members came together to identify the challenges and opportunities associated with this initiative, major research ideas, and ways to position UIUC as a leader of transportation research.
For a full view of the kick-off STII meeting, please click here.
In his opening remarks, Vice Chancellor for Academic Affairs and Provost Andreas Cangellaris said that this initiative is set not only to bring the entire UIUC campus together but also to strengthen collaboration between three Illinois campuses—UIUC, the University of Illinois at Chicago (UIC), and Northwestern, serving as the umbrella through which all transportation research will be coordinated. STII will also unite industry and national laboratories and Chicago’s role as a global hub should help promote the initiative’s mission, according to Cangellaris.
Also at the meeting, Al-Qadi shared recent national transportation statistics, touching on the national impact of the sector on the environment and the main challenges hindering national transportation development. Congestion costs—estimated at an annual $160 billion—inadequate revenues, the nation’s vulnerability to disasters, and the gap between institution’s missions and their preparedness to address those missions were highlighted as some of the key hindrances.
“Having identified our strengths and challenges, we need to focus now on developing a roadmap for addressing our connectivity needs and drafting our policy agenda,” Al-Qadi said. “Only then we’ll be able to facilitate the integration and deployment of new concepts and technologies in areas such as sensing and control systems, internet of things, autonomy and connectivity, and several others.”
Last year, a team of faculty from several schools at UIUC, in collaboration with peers from UIC and Northwestern, put together a vision for the Illinois Automated and Connected Track (I-ACT). Connected and autonomous vehicle technologies are expected to bring users greater convenience, seamless and safer mobility, and connected life in a digitalized world; for cities and operators, the benefits are greater efficiencies and better utilization of resources. In the context of commercial vehicle systems and freight supply chains, driverless vehicles will enable new forms of mobility supply, car sharing, integration between personal transportation and public mobility, and efficient and accessible travel service in high-density cities.
Proposed to be housed within the ATREL facilities, the I-ACT test track is aimed to accelerate the development and deployment of automated transportation, while ensuring safe and efficient mobility and operations and capitalizing on public benefits. STII is well positioned to coordinate the work needed to transform this collective vision to reality.
The second meeting of STII is tentatively scheduled for Spring 2018. If you are interested in learning more about the activities of STII, please join the notification list.
Vice Chancellor for Academic Affairs and Provost Andreas Cangellaris opened the STII kick-off meeting.
Faculty across campus attending the kick-off meeting of the Smart Transportation Initiative.
A discussion of main challenges at one of the breakout sessions moderated by Professor Bill Spencer of the Department of Civil and Environmental Engineering.
LCA Tool Developed to Assess Environmental Impact of Pavement Treatments
Over the past few decades, there has been an increasing level of awareness toward using recycled materials as an alternative to virgin materials in flexible pavements and, thus, recycling has become an integral part of road maintenance and rehabilitation activities.
Among the most commonly used recycling techniques are hot in-place recycling (HIR), cold in-place recycling (CIR), and full-depth reclamation (FDR). In each of these methods, existing pavement materials are removed and reused, allowing for surface distresses to be corrected in place. The ultimate objectives are to conserve virgin materials; reduce energy use, environmental impacts, construction time, traffic flow disruptions, and number of hauling trucks; and improve pavement conditions.
HIR is based on softening the existing pavement surface using heat, removing the pavement surface and mixing it with asphalt binder—and possible virgin aggregate—and re-placing the recycled material on the pavement. In the CIR technique, the distressed pavement surface is pulverized and the recycled material is then mixed with new materials and compacted back in place; thus, providing an improved base layer with the addition of a wearing hot-mix asphalt overlay. The only difference between the CIR and FDR methods is that in the latter the whole thickness of the existing asphalt concrete layer—plus a predetermined thickness of at least two inches of the underlying unbound granular layer—are pulverized and mixed together into a homogenous mixture before compaction, producing a stabilized layer.
Recently, researchers from the University of Illinois at Urbana-Champaign’s Illinois Center for Transportation (ICT), University of California-Davis, and Rutgers University teamed up to develop a user-friendly life-cycle assessment tool to assess the environmental impacts and energy use of transportation projects that involve maintenance and rehabilitation treatments using the above in-place recycling and conventional paving methods. The study, sponsored by the Federal Highway Administration, was conducted by a team of researchers led by ICT Director and Bliss Professor of Engineering Imad Al-Qadi as Principal Investigator.
The developed tool uses data, simulation, and models throughout the in-place recycling stages for pavement life-cycle assessment, including materials, construction, maintenance/rehabilitation, use, and end-of-life stages. “The developed tool is expected to help pavement industry practitioners, consultants, and agencies complement their projects’ economic and social assessment with environmental impacts quantification and allow them to select an optimum rehabilitation alternative technique based on service life performance and environmental impact,” Al-Qadi said.
The study also emphasized the main factors that impact emissions arising and energy consumed at every stage of the pavement life-cycle as a result of in-place recycling techniques. Therefore, the research team gathered detailed information about fuel usage associated with such techniques based on field data. They found that fuel usage is affected by pavement aggregate hardness, pavement width, air temperature, and horsepower of the equipment used.
Mouna Krami Senhaji, one of the graduate students who have assisted with the project, says that it is important that agencies understanding of maintenance and rehabilitation alternatives be enhanced for sound decision making when selecting and prioritizing projects. “The newly developed tool provides the opportunity to analyze the environmental impacts and performance of a wide range of treatments applicable to flexible pavements, so stakeholders around the nation will be able to accurately evaluate the benefits of in-place recycling versus conventional methods.”
Rutgers Civil and Environmental Engineering associate professor Hao Wang considers the study particularly significant for east coast where high volumes of freight traffic on highways is a daily occurrence. “In-place recycling techniques significantly reduce traffic delays because they result in shorter periods of lane closures.”
Keeping It Together: An In-Depth Examination of Various Tack Coats
Similar to frosting in a layered cake, which holds the multiple layers together, interface bonding in road pavement structures ensures that the asphalt layers remain in place for longer periods of time.
The current interface bonding procedure includes the use of tack coats. According to the Asphalt Institute, a tack coat is a light application of bituminous materials to an existing surface using a distributor to provide sufficient bonding between pavement layers. The most common tack coats on the market are hot asphalt products and emulsified asphalts. Hot asphalt products are a blend of petroleum-based asphalt binder and sometimes a modifier. Emulsified asphalts (emulsions) are products made of asphalt cement, an emulsifying agent, and water.
In a previous research collaboration between the Illinois Department of Transportation (IDOT) and Illinois Center for Transportation (ICT), an interface shear test device (ISTD) was developed to characterize the bonding strength of pavement interlayer in the laboratory under Project R27-100, Best Practices for Implementation of Tack Coat: Part 1 - Laboratory Study.
However, the ISTD was developed for a hydraulic testing frame—something that is customized and not easily accessible. Therefore, there was a need for a simplified design of the shear fixture for local agencies and contractors—many who do not have servo-hydraulic loading devices—to perform routine performance tests on tack coats.
ICT and IDOT teamed up again in Project R27-SP34, “Evaluation of Various Tack Coat Materials Using Interface Shear Device and Recommendations on a Simplified Device,” to evaluate the properties of various tack coat materials, and provide recommendations for a simplified shear testing device that can be integrated into the testing frames at IDOT.
The project was conducted under the direction of a Technical Review Panel (TRP) chaired by James (Jim) Trepanier, HMA Operations Engineer at IDOT’s Central Bureau of Materials. According to Jim, as night paving is becoming more common the need for tack coats with reduced cure time has become a high priority. In addition, there are a number of tack coat options that have little or no cure time that are currently not listed as acceptable tack coats in the Department’s specifications.
“This project was initiated in order to evaluate the effectiveness of these products for possible inclusion in IDOT’s specifications,” Trepanier said.“The addition of these new tack coat products will increase productivity and shorten the time needed for construction, thus minimizing safety concerns and maximizing cost savings to the contractor, IDOT, and ultimately the tax payer.”
Dr. Hasan Ozer served as principle investigator (PI) on this project. Ozer is a research assistant professor in the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign (UIUC).
“There are various types of tack coat materials in the market place used in original pavement construction and rehabilitation projects,” Ozer said. “However, it is important to select the right material and use the optimum application rate to maximize bonding between different layers.”
Also assisting with this project was graduate research assistant Jose Rivera-Perez, who is pursuing his master’s degree in civil engineering at UIUC.
In this latest study, the research team evaluated the interface shear strength of seven tack coat materials using the ISTD by testing the composite specimens consisting of concrete and hot-mix asphalt mixture (HMA). Four of the tack coats were hot-applied products and three were emulsion.
“The ISTD has been very useful in making the right choices when it comes to selection and application of tack coat materials,” Ozer said.
Overall, the research showed that, at the same application rate, hot-applied products have significantly higher shear strength than the emulsion products.
The research team also conducted a separate round of preliminary tests on a simplified shear testing device and found that it is important to control normal pressure build-up within the device. Therefore, recommendations were made to modify the simplified shear testing device to conform to the ISTD that has been used in this study and previous studies.
The final report detailing the results of the research project is availablehere.
Research Looks to Decrease Road Closure Times in Illinois
Imagine you’re in your car sipping coffee and hoping for a smooth commute when you’re greeted by those big, orange signs. Construction. Still? This has been going on for weeks and the traffic is now the source of your daily headache. What is worse is it looks finished. Why can’t they just open the road?
That’s the problem being looked at in Project R27-154, “Effect of Early-Age Concrete Elastic Properties on Fatigue Damage in PCC Pavements Containing Fibers.” It’s a problem that is magnified by an increase in traffic throughout the state. The project was conducted by Illinois Center for Transportation (ICT) researchers and the Illinois Department of Transportation (IDOT) under the direction of a Technical Review Panel chaired by James Krstulovich,Concrete Technology Engineer at IDOT’s Central Bureau of Materials. Professor Mohsen Issa was the project’s principal investigator (PI).
Researchers have been searching for a way to keep road closure times down while also not compromising the life-span of new concrete pavements. Keeping road closure times down will not only help reduce traffic but save money too.
Currently, the earliest pavement will be opened to traffic is when test specimens have attained a flexural strength of 650 pounds per square inch (psi) or a compressive strength of 3,500 psi. Similar criteria apply to concrete patches. In order to open a patch as quickly as possible, an accelerating chemical admixture could be added to the concrete mix, or the mix could be designed to have a larger volume of cement. However, such methods could ultimately compromise the long-term durability of the concrete.