The Center for Sustainable & Resilient Infrastructure (CSRI) is a partnership between VTTI and Virginia Tech's Via Department of Civil and Environmental Engineering (CEE) Transportation Infrastructure and Systems Engineering (TISE) Program. The mission of CSRI is to envision, develop and deploy innovative, safe, efficient, sustainable, and resilient solutions for re-inventing, renewing, and managing our infrastructure facilities, networks, and systems, while educating the next generation of transportation professionals to have a solid academic foundation, be creative and resourceful, and appreciate the social, economic, and environmental impacts of our profession.
Our infrastructure systems are key for supporting economic growth, sustainable development, and quality of life. However, many existing infrastructure systems (roads, power, water distribution, etc.) do not provide the level of service that society demands. Many have deteriorated because of use, misuse, and environmental factors, or they have become functionally obsolete because of changing demands and technological developments. Furthermore, the current confluence of disruptive technological changes underway (e.g., smart cities, smart infrastructure, automated vehicles, multifunctionality, high-tech construction, sustainable energy, advanced materials) coupled with increasing demands imposed by climate change and global sociopolitical and economic macrotrends, have created an urgent need to re-invent and modernize our transportation services, making them safer, more efficient, sustainable, resilient, and equitable.
CSRI is recognized globally as a leader in transportation infrastructure research and education and supports the full research cycle, including conceptualization, basic and applied research, development, and implementation. The center houses the Vehicle Pavement Interaction, Structural Evaluation, and Accelerated Pavement Testing Research Programs, operates state-of-the-art laboratories and facilities, collaborates with colleagues from different departments, colleges, agencies and institutions, and regularly supports up to 40 graduate and undergraduate students.
In the field of transportation safety, CSRI research has contributed to a fundamental understanding of the interaction between the vehicle and the road, which has led to safe and comfortable mobility and access with minimum transportation cost and environmental pollution. This $9.6M initiative had its genesis in a series of national Transportation Pooled Funds, initiated in cooperation with the Virginia Department of Transportation (VDOT) and the Virginia Transportation Research Council (VTRC), aimed at improving the functional characteristics of our road infrastructure. We coupled these efforts with funding from the National Science Foundation, Federal Highway Administration, National Cooperative Highway Research Program, VDOT and other State DOTs to produce practical, implementable policies, tools, and guidance. We developed, tested, and deployed a number of innovations, including a systemic approach for incorporating safety into transportation asset management, a novel approach to evaluate the safety of pavement and bridges using smart vehicle and tire technologies, and robust splash-and-spray and hydroplaning models and assessment tools. Our research products have been adopted by the Federal Highway Administration (FHWA), the American Association of State Highway and Transportation Officials (AASHTO), and ASTM international as standard guidance and protocols, and have already resulted in significant safety improvements to reduce crashes and associated fatalities.
To enhance the structural health assessment of transportation infrastructure, CSRI has led a large initiative that: evaluated these technologies as part of the Second Strategic Highway Research Program, demonstrated the advantages of the technology and developed innovative approaches and policies to use the information to enhance asset management decisions, implemented the enhanced decision processes in Virginia, and supported the nationwide deployment and implementation of the innovations through a pooled-fund effort. These innovations are producing important maintenance and rehabilitation savings for transportation agencies globally.
To help incorporate sustainability and resilience considerations into asset management, CSRI has developed efficient and practical life-cycle cost and environmental assessment tools, established frameworks to link data collection with the decision process and to improve the quality of the big data collected, and created new multi-criteria and artificial intelligence approaches for managing the performance of our transportation infrastructure and allocating resources across different transportation asset types. We have also collaborated with colleagues from around the world to incorporate sustainability, vulnerability, and resiliency considerations into the infrastructure management decision-making processes. The results of these efforts are helping reduce the negative impacts of transportation on the environment.
In the pavement engineering field, we have partnered with VDOT and VTRC to establish the Virginia Accelerated Pavement Testing program that has developed and supported the implementation and deployment of better pavement and material testing, assessment, design, analysis, and management tools. This collaboration has positioned the Commonwealth of Virginia as a world leader in pavement and materials research and education, and is cited as an exemplar of fruitful collaboration between government, academia, and industry.
INNOVATION: CSRI has developed, tested and deployed a number of innovations, including a systemic approach for incorporating safety into transportation asset management, novel approaches to evaluate the safety of pavement and bridges using smart vehicle and tire technologies, robust splash-and-spray and hydroplaning models and assessment tools, effective big data approaches for effectively assessing pavement structural capacity at highway speeds, and tools for life-cycle cost and environmental assessment of transportation infrastructure.
INDUSTRY BEST PRACTICES: CSRI research products have been adopted by the Federal Highway Administration (FHWA), the American Association of State highway and Transportation Officials (AASHTO) and ASTM International as standard guidance and protocols. Among other efforts, CSRI has worked with FHWA and NCHRP to develop standards for network level measurement of friction, macrotexture and pavement structural capacity.
SUSTAINABILITY: CSRI has developed approaches, guidance, and tools that are being used by transportation agencies around the world and have resulted in significant safety improvements to reduce crashes and associated fatalities, enhanced asset management decisions, and more sustainable and resilient pavements.
OUTREACH: CSRI has contributed to enhance the transportation infrastructure body of knowledge with more than 400 journal articles, conference papers, reports, manuals, and magazine articles and 300 presentations, including many keynote presentations at international venues. We have also organized several national and international conferences in Virgnia, including the principal conferences in the world in the areas of vehicle-pavement interaction and pavement asset management.
EDUCATION: CSRI has championed the incorporation of asset management and sustainability concepts into the Civil and Environmental Engineering curriculum. The center has initiated and led a series of Infrastructure Management Research and Education Workshops sponsored by the National Science Foundation, FHWA and the Transportation Research Board (TRB). These workshops have provided a forum for the exchange of ideas, best practices, and know-how on asset management education and has been incorporated by the National Academies of Sciences Engineering and Medicine as a formal TRB Subcommittee on Asset Management Education.
The overall goals of this FHWA-funded project are to:
Develop and advance new, improved approaches to measuring road friction,
Establish new best practices for PFM that explicitly address safety performance,
Provide assistance toward implementation, and
Develop marketing products to support institutionalization on a national level.
The effort is demonstrating that novel approaches to measuring road surface characteristics provide a more effective means than the traditional friction-measuring approaches for safety analysis, establishing best practices for PFM that explicitly addresses safety performance through a data-driven approach , and developing and demonstrating a robust methodology to develop Crash Modification Factors (CMFs) and/or Functions (CMFunctions) and friction intervention thresholds based on the obtained SPFs. In addition, the team is providing assistance for implementation through customized instances of technical assistance using the extensive experience of the research team and the findings of this project, and developing outreach and marketing products to accelerate use and institutionalization of the developed methodology on a national level.
NCHRP 10-98 Protocols for Network-Level Macrotexture Measurement
This project developed recommended protocols for test methods, equipment specifications, and data quality assurance practices for network-level macrotexture measurement. The project identified equipment, environmental, and operational factors that influence macrotexture measurements, the macrotexture characterization parameters used to represent the macrotexture, and improved methods for network-level macrotexture measurement that address these factors. The project included pavement data collection in cooperation with several industrial partners in Virginia, Minnesota, and Texas. Deliverables included a Final Report and three draft AASHTO protocols for macrotexture measuring equipment specifications, operational procedures for collecting data, and certification procedures for equipment to facilitate use of these methods.
NCHRP 15-55 Guidance to Predict and Mitigate Dynamic Hydroplaning on Roadways
This project developed guidance to better predict and mitigate hydroplaning potential on roadways to help transportation agencies identify areas with a high potential of hydroplaning, and to evaluate and select appropriate mitigation solutions. The guidance includes an enhanced definition of hydroplaning potential based on the physics behind hydroplaning. A key focus of this research was to the development of a research-grade model to address existing gaps, propose a novel definition of hydroplaning, and determine the impact of the various roadway and vehicle factors. The project then used the results of the integrated model to developed simplified relationships, which were implemented in a tool developed to apply the integrated hydroplaning model without the need of commercial software. This tool provides highway engineers with practical and simple means for assessing hydroplaning potential.
Pavement Friction Management Program Pilot Demonstration
This project evaluated 7,000 miles of the highways in the Commonwealth of Virginia. The demonstration included collection of friction, macrotexture and geometric data, processing and filtering the data, and conducting a systemic analysis of the network. The analysis investigated the relationship between crashes and friction and other roadway properties and developed Safety Performance Functions (SPF) to quantify this relationship. The SPFs were then used in an Empirical Bayes analysis to estimate crash counts before and after friction improvement treatments and identify sections with friction deficiencies that may benefit for a friction treatment.
FHWA Pavement Friction Management Support Program
This effort consisted of two phases:
Development of Pavement Friction Management Programs, and
The Acceptance Testing and Demonstration of the Continuous Friction Measurement Equipment.
The main products of this effort were (1) a novel proactive methodology to reduce roadway crashes and associated fatalities based on managing the road surface functional and geometric characteristics, developing SPFs that incorporate these parameters, and using these functions to prioritize friction improvement projects based on a benefit cost analysis; (2) pilot deployment of the methodology in four states (including Washington State); (3) a draft AASHTO standard for friction equipment; and (4) a proposed addendum to the AASHTO Guide for Pavement Fiction.
Evaluation of Methods for Pavement Surface Friction Testing on Non-Tangent Roadways and Segments
This project, which was sponsored by the North Carolina DOT, explored the use of CPFM as a tool for PFM. The main research products included:
A comparison of friction obtained from three different equipment types and methodologies,
Recommendations regarding the feasibility of defining investigatory and critical friction limits, and
Implementation guidance for continuous friction testing technology for the North Carolina DOT.
NSF Estimating Tire-Road Friction from Probe Vehicles
This project developed and implemented a theory to describe the tire/road contact mechanics processes and the resulting friction properties, and conducted experimental testing to support the development and validation of the proposed model in the laboratory and on the track. The project integrated knowledge from mechanical engineering and civil engineering to produce a significant leap forward that will transform how tire-road friction is evaluated. The availability of real-time, vehicle-based estimation of hazardous slippery driving condition will improve operations in transportation agencies and the safety of the driving public. It combined sensor-based friction estimation algorithms with model-based friction estimation algorithms to determine tire-road friction for road surface conditions using a range of theoretical and computational modeling methods including vehicle and tire dynamics modeling , signal processing (time-frequency analysis), neural network for tire input-output parameters estimation, and a fuzzy logic algorithm for road surface condition classification.
The main project products include an improved real-time estimate of tire-road friction levels under various weather conditions. This information helped improve the understanding of the interaction between road friction, road surface condition, and crash risk. In the future, such technology could be used to provide continuous real-time data about roadway friction levels and pinpoint the time when roadway conditions become slippery and hazardous.
Pavement Structural Evaluation With Traffic Speed Deflectometers (TSDs)
This $4.8 Million project brings together 26 state highway agencies and the Federal Highway Administration in a research consortium focused on providing guidelines on how to specify collection and use data collected with TSDs for network- and project-level pavement management application. Specific tasks of the pooled fund include:
Collect sample TSD data for each participating agency.
Document the different TSD technologies, their measurement characteristics, the data analysis methods that have been used with TSD data and applications of TSDs for network- and project-level pavement management.
Developed guidelines for data collection and guidelines to incorporate information derived from TSDs into the pavement management decision making process.
Develop case studies showing how TSDs can be used to support project-level decision making and the resulting return on investment.
Organize and deliver workshops and training material for the pooled fund members.
The results of this pooled fund will allow agencies to effectively use TSD-derived structural information to come up with better and more cost-effective maintenance decisions. Early results show a return of investment of at least 4 from TSD testing.
National Sustainable Pavement Consortium
The objective of the pooled-fund project (TP- 5(268)) was to establish a research consortium focused on enhancing pavement sustainability. To accomplish these objectives, the project:
Developed a tool (in cooperation with the University of Coimbra) to assess the economic and environmental impacts of pavement and apply this tool in series of case studies that show the benefits of in situ pavement recycling,
Applied the tool to develop serval case studies to showcase how to apply life-cycle thinking to make better pavement decisions and included the following main efforts and associated peer-reviewed publications,
Investigated the potential impact of climate change on pavement design and management practices,
Synthesize long-term performance data from states with active in-place recycling programs, and
Conducted several outreach, educational, technology transfer, and international exchange activities, including sporting several International Symposium on Pavement LCA and representing in FHWA in a twining program with the European project LCE4Roads.
Flintsch, G.W., de León Izeppi, E., Bongioanni, V., Katicha, S., Meager, K., Fernando, E., Perera, R., McGhee, K.K., NCHRP Research Report 964 Protocols for Network-Level Macrotexture Measurement, NCHRP, Washington, DC, 156 pp.
de León Izeppi, E., Katicha, S., Flintsch, G.W., McGhee, K., McCarthy, R., Smith, K., Pavement Friction Management Program Utilizing Continuous Friction Measurement Equipment and State-of-the-Practice Safety Analysis Demonstration Project, Report No. FHWA-RC-20-0009, Sep 2019, Federal Highway Administration, Washington, D.C (in print).
Flintsch, G.W., Smith, B.L., Infrastructure Pavement Assessment & Management Applications Enabled by the Connected Vehicles Environment – Proof-of-Concept, Final Report, Connected Vehicles- Infrastructure University Transportation Center (CVI-UTC), Virginia Tech Transportation Institute, 2015. Blacksburg, VA, 13 pp. http://cvi-utc.org/wp-content/uploads/2015/10/Flintsch_Final.pdf.
de León Izeppi, E., Morrison, A., Flintsch, G.W., McGhee, K.K., Best Practices and Performance Assessment for Preventive Maintenance Treatments for Virginia Pavements, Virginia Transportation Research Council, VTRC 16-R3, 2015, Charlottesville, VA, 58 pp. http://vtrc.virginiadot.org/PubDetails.aspx?PubNo=16-R3.
Flintsch, G.W., Tang, L., Katicha, S.W., de León, E., Viner, H., Dunford, A., Nesnas, K., Coyle, F., Sanders, P., Gibbons, R., Williams, B., Hargreaves D., Parry, T., McGhee, K., Larson, R.M., and Smith K. (2014), Splash and Spray Assessment Tool Development Program, Final Report, 2014, DTFH61-08-C-00030. http://hdl.handle.net/10919/50550.
Bryce, J., Flintsch, G.W., Katicha, S., and Diefenderfer, B.,, Network-Level Structural Capacity Index for Network-level Structural Evaluation of Pavements, Virginia Center for Transportation Innovation and Research, VCTIR 13-R9, 2013. Charlottesville, VA, 63 pp. http://www.virginiadot.org/vtrc/main/online_reports/pdf/13-r9.pdf.
Flintsch, G.W., Katicha, S.W., Bryce, Ferne, B., J., Nell, S., Diefenderfer, B., Assessment of Continuous Pavement Deflection measuring Technologies, Second Strategic Highway Research Program (SHRP 2), S2-R06F-RW-1, 2013, The National Academies, Washington, DC. http://onlinepubs.trb.org/onlinepubs/shrp2/SHRP2prepubR06F.pdf.
This recently completed project for the Virginia Department of Transportation (VDOT) included structural testing with the TSD on 1,500 miles of interstate roads and 2,520 miles of primary roads in Virginia.
CSRI has partnered with the Virginia Department of Transportation (VDOT) and the Virginia Transportation Research Council to establish, operate and manage Virginia's Accelerated Pavement Testing Facility.
Implementation of Network Level Pavement Structural Testing into Virginia Pavement Management
Network Level Pavement Structural Testing with the Traffic Speed Deflectometer
This recently completed project for VDOT included structural testing with the TSD on 1,500 miles of interstate roads and 2,520 miles of primary roads in Virginia. The two main objectives of the project were to 1) determine the levels of pavement structural response that define structurally good, fair, and poor pavements and 2) determine the impact of including the structural information on VDOT's network-level pavement maintenance and rehabilitation decision-making process. Specific major tasks include:
TSD data collection and processing (4,020 total miles),
Ground penetrating radar data collection on primary roads to support pavement structural evaluation (2,520 miles),
Evaluate the different structural parameters or indexes that can be used to characterize the pavement structural condition and recommend the most appropriate one(s), and
Demonstrate that the pavement structural condition has an impact on the pavement surface deterioration and develop pavement surface deterioration curves that incorporate the impact of the structural condition.
Findings from this project were crucial in VDOT's decision to 1) replace the outdated structural information in its pavement management system obtained from Falling Weight Deflectometer (FWD) testing with the newly collected structural information obtained from the TSD and 2) develop webinar and training material on how to use and interpret TSD data for VDOT district level engineers.
TSD data Implementation and District Level Training
VDOT has collected more than 5,000 miles of structural data with the Traffic Speed Deflectometer (TSD). The objectives of this project are to: (1) integrate the data collected into the pavement management system, (2) develop training material on how to effectively use the network level structural evaluation data collected by the TSD, and (3) deliver a series of regional training sections. The material will be specifically targeted to district engineers and presented through workshops and/or webinars in the form of case studies.
In terms of the project benefits, the use of up to date TSD structural information in the pavement management system will result in more accurate recommended maintenance activities. The structural information and training material will allow the district engineers to select, scope and design more appropriate maintenance and rehabilitation strategies. Furthermore, it will allow a better delineation of the spatial scope of potential suspected structural problems; that is, it will allow the district engineers to determine where on the road observed distresses are most likely caused by a structural problem and where they are most likely caused by other problems (e.g. mix problems). This can result in significant maintenance savings.
Operation and Management of the Virginia Accelerated Pavement Testing Facility
CSRI has partnered with VDOT and the Virginia Transportation Research Council to establish, operate and manage Virginia's Accelerated Pavement Testing Facility. This includes supporting VDOT on the identification of research questions, designing of the experiments, supervising the construction, and instrumenting the sections, as well as maintaining and operating the equipment, monitoring the experiments, collecting and analyzing the data, preparing reports, technology transfer and overseeing the implementation of the findings. So far, this effort has allow to:
Investigate the effect of different overlays on the rutting response of the CCPR material under accelerated loading,
Compare the rutting performance of dense graded asphalt mixtures having different volumetric properties as a result of reducing design gyrations from 65 to 50 during mixture design,
Evaluate the use of modified surface layers (with fibers and asphalt-rubber) to delay reflecting cracking on jointed concrete pavements, and
Support the implementation of Balance Mix Design for improving asphalt mix performance in Virginia.