Sustainable Systems

Cycle Atlanta smartphone app
Researchers track the microbial communities along a Florida Panhandle beach after the Deepwater Horizon oil spill.
Joe Brown and Andrew Loo hold test tubes with water that has been tested for E coli bateria. The purple water is contaminated.
Solar panels atop Clough Undergraduate Learning Commons on the Georgia Tech campus.
Students test water samples in Nicaragua.

The world’s population is projected to exceed 9 billion people in the coming decades, according to current population estimates from the United Nations.

Almost all of that growth will come in emerging economies, where the lack of modern infrastructure leads to a variety of health concerns — poor access to water or poor water quality, air pollution, inadequate systems for the collection or treatment of wastes and trash.

Cities offer opportunities for accommodating this growing population — lower per-capita energy consumption, concentrated jobs and social resources, efficiencies in delivering all manner of services that support our civilization. Cities also present their own problems, accounting for roughly three-quarters of all energy use and carbon emissions on the planet and placing a significant burden on the environment.

Yet, while two-thirds of the world’s population will be concentrated in dense, urban areas by 2050, the other third will remain in rural communities where the challenge for engineers is to create effective infrastructure and deliver services to a scattered population that has very different transportation and energy needs than city-dwellers.

Researchers in CEEatGT are already imagining how we can approach these issues and create communities that grow responsibly while meeting the needs of the people who live in them:

We are working to preserve and renew our existing infrastructure systems — within our budget constraints — including creating new and innovative ways to detect operational problems and prioritize our expenditures.

We are working to develop technologies and processes that can improve global public health, designing for scarcity, scalability and resilience.

We are working to understand how our infrastructure systems interact and depend on one another to function and use that knowledge to improve their reliability.

We are working to analyze human behavior and the choices people make so we can adequately plan our future development while balancing the interests of rural areas and a growing urban population, accounting for their dissimilar needs.

We are working to study the relationships between the built environment and our transportation systems so we can improve community designs to foster mobility, encourage healthy living, and balance economic opportunities with personal well-being.

Meanwhile, our climate is changing, forcing us to consider the impact on the availability and use of water, how we produce energy, and how we use our land. We need to mitigate these impacts on human society, including planning our communities and our transportation systems to encourage energy-efficient mobility.

And all of this must be done with an eye toward resource consumption. We must build these systems and processes in an environmentally sensitive way.

A Systems Approach to Improve Predictions of Biodegradation and Ecosystem Recovery in Coastal Marine Sediments Impacted by Oil SpillsAfter coastal oil spills, petroleum hydrocarbons accumulate in submerged nearshore sediments and on beaches, poisoning these ecosystems and creating health risks for coastal organisms and humans. Erosion and deposition cycles lead to burial of weathered crude oil in submerged shelf beds, intertidal sediments, and dry beach sands. Prediction of the effects and fate of these buried petroleum hydrocarbons remains hampered by our limited understanding of the controls of the biodegradation and functioning of sedimentary microbial communities that break down petroleum hydrocarbons. The main goals of this project are to link microbial degradation of buried oil and associated transport processes, and to integrate these data in a model that allows predictions of pathways and rates of oil degradation, and thus, forecasting recovery pathways in future oil spills.
Sponsor: Gulf of Mexico Research Initiative
Co-Principal Investigator: Kostas Konstantinidis
Bicyclist Facility Preferences and Effects on Increasing Bicycle Trips – This project aims to understand how both current and potential cyclists respond to different types of cycling infrastructure. The end goal is to quantify the demand that is generated through mode and route shifts by introducing new infrastructure using extensive surveys and focus groups.
Sponsor: National Cooperative Highway Research Program
Principal Investigator: Kari Watkins
Developing Georgia’s High Friction Surface Treatment (HFST) Program to Improve Roadway Safety – The objective of this project is to collect and analyze detailed, location-referenced HFST site characteristics data. The study uses emerging sensing technologies, including 2D imaging, lasers, 3D LiDAR, Inertia Measurement Units (IMU), and GPS/GIS technologies with machine learning and artificial intelligence to a) analyze the changes in site characteristics before and after HFST installation; and b) group and analyze the detailed site characteristics on curves with similar ball bank indicator values but very different run-off-road crash rates.
Principal Investigator: James Tsai
Developing Low-Carbon Cities in the USA, China & India through Inter-Disciplinary Integration Across Engineering, Environmental Sciences, Social Sciences & Public Health - A five-year project that will contribute to the development of low-carbon, sustainable cities in the U.S., India, and China. The research effort is two-pronged, focusing on reducing greenhouse gas emissions in selected cities and also addressing broader sustainability goals such as economic development, water scarcity, environmental pollution, climate change, and public health.
Sponsor: National Science Foundation Partnerships for International Research and Education (PIRE)
Co-Principal Investigator: Armistead Russell
Development of Metagenomics-Based Method for Improving Detection of Foodborne Pathogens – This project will identify and test the discriminatory power of gene signatures for Shiga toxin-producing Escherichia coli (STEC) to establish biomarkers that robustly distinguish STEC from innocuous relatives adapted to environmental niches; establish bioinformatics protocols that enable reliable detection of these biomarkers in produce-associated microbial community through sequence-based, culture-independent diagnostic tests; and apply the developed method to characterize the interactions between produce-associated microbial communities and STECs under pre- and post-harvested conditions.
Sponsor: U.S. Department of Agriculture
Principal Investigator: Kostas Konstantinidis
ERC: Center for Bio-mediated and Bio-inspired Geotechnics – This National Science Foundation Engineering Research Center explores what nature can teach us about the way we practice geotechnical engineer. The discoveries researchers make could mean significant improvements in how we clean up environmental contamination, harden structures against natural and man-made disasters, make infrastructure construction more efficient, or improve the effectiveness of natural resource recovery operations.
Sponsor: National Science Foundation
Co-Principal Investigator: David Frost
Financial Feasibility Analysis of Alternative Energy Sources
Sponsor: Royal Institution of Chartered Surveyors
Principal Investigator: Baabak Ashuri
Impacts of Information and Communication Technology (ICT) on Travel Behavior – This series of projects has explored the ways in which ICT has influenced and is influencing travel behavior. Many activities can now be done online, which can save the trip required to conduct it in person. On the other hand, ICT can stimulate additional travel by saving time and money in other ways and by giving ready access to information about activities, people, and places. Thus, it is important to better understand these counteracting influences, so as to suggest ways in which the two-edged sword of improved ICTs can be deployed to maximize sustainability.
Sponsors: Various
Principal Investigator: Patricia Mokhtarian
Implementation of an Enhanced COPACES for Georgia’s Counties and Cities – Development and deployment of a tool for local transportation agencies, including counties and cities, to cost effectively manage their pavement assets.
Sponsor: Georgia Department of Transportation
Principal Investigator: James Tsai
Linking Salt Rock Deformation Regimes to Microstructure Organization – Microstructure-enriched model of damage and healing for salt rock: Using micrographs and deformation measures obtained during creep tests performed on granulat salt to link microstructure descriptors to continuum mechanics variables of damage and healing. The model allows for predicting changes of stiffness and permeability in salt rock subject to tensile crack propagation, compressive crack closure and crack rebounding driven by sodium ion Diffusive-Mass Transfer. Further work will be dedicated to the implementation of the model in Finite Element Method-based programs to simulate the evolution of the Excavation Damaged Zone around geological storage facilities used for nuclear waste, natural gas, compressed air and hydrogen.
Sponsor: National Science Foundation
Principal Investigator: Chloe Arson
Making a Business Case for Sustainability – The effects of green building certification on housing prices in metropolitan Atlanta.
Sponsor: Southface Energy Institute
Principal Investigator: Baabak Ashuri
Modeling Ballast Particle Crushing as a Phase Change – Size and shielding effects on single particle crushing: A DEM model of crushable ballast particle was designed and calibrated against experimental results of uniaxial compression tests on single sand grains. The calibrated model was then used to study the influence of the coordination number on the peak force at initial failure ("shielding effects"). On-going research focuses on the influence of particle size on particle strength, the micromechanical processes of crushing in granular assemblies subject to under monotonic and cyclic loading, and on the forms of energy dissipated by an assembly of bonded aggregates during crushing.
Sponsor: Association of American Railroads, Affiliated Laboratory for Railway Research
Principal Investigator: Chloe Arson
Persistence of Molecular Markers Used in Fecal Source Tracking: Metagenomic-Based Assessment of Microbial and Human DNAWith the relatively new molecular biological tools, the identification of fecal contamination in the environment increasingly makes use of rapid molecular assays to identify DNA sequences specific to fecal indicator bacteria or DNA from host-specific cells such as mitochondrial DNA (mtDNA) shed in stools. Unknowns persist, however, primarily regarding the kinetic relationships between culture-dependent and culture-independent assays, since time-since-contamination information is critical in surveillance as a proxy for fecal pathogen survival and therefore public health risk. This work will elucidate the strengths and limitations of current and novel molecular assays intended to identify fecal contamination in environmental waters.
Sponsor: National Science Foundation
Principal Investigator: Joe Brown
Co-Principal Investigator: Kostas Konstantinidis
Population Density, Sanitation, and Health in Urban Maputo – Evaluating the impact of improved latrines on children's health in developing countries. The project, which will assess whether children are actually healthier as a result of better sanitation, tests decentralized sanitation systems in an urban area, the first study of its kind.
Sponsor: U.S. Agency for International Development
Principal Investigator: Joe Brown
Productive Reuse of High Organic Carbon Content and Biomass Fly Ash – Development of reuse alternatives for fly ash that is traditionally sent for land disposal.
Sponsor: Southern Company
Principal Investigators: Susan Burns and Kimberly Kurtis
Regional Industrial Structure, Economic Resilience and Energy Consumption: Comparative Evaluation, Historical Analysis and Pathway towards a More Sustainable Economy – Understanding of how regional economic activities and energy use interact with each other is incomplete. We need to better understand these interactions to be able to develop a more sustainable economy. The project will comprehensively evaluate the economic impact and the rebound effect of increased energy efficiency (e.g., energy use for lighting has increased with every increase in lighting efficiency) by introducing the concept of structural adjustment cost (SAC) into the computable general equilibrium CGE model. The study will also investigate how the impact of an energy efficiency shock diffuses through the entire economic system accounting for industry interaction and compare the heterogeneous impact of the same shock on states with different resilience rankings.
SEES: Interactions of Food Systems with Water and Energy Systems Supplement (FEW): Opportunities, Challenges, and Implications of a Nutrient Grid – The project is developing a systems dynamics model of complex urban infrastructure systems, then using it to quantify the resilience of urban infrastructure systems for each of four urban development strategies independently and in combination: 1) low impact development, 2) combined cooling, heating, and power systems, 3) electrification of transportation, and 4) urban farming.
Sponsor: National Science Foundation
Co-Principal Investigator: John Crittenden
Remote Sensing and GIS-enabled Asset Management System (RS-GAMS) – Development and validation of intelligently and cost-effectively inventorying roadway assets and evaluating their condition using emerging sensing technologies, including 2D imaging, lasers, 3D LiDAR, UAV, GPS/GIS technologies with artificial intelligence and machine learning.
Sponsor: U.S. Department of Transportation
Principal Investigator: James Tsai
Resilient Interdependent Infrastructure Processes and Systems: Participatory Modeling of Complex Urban Infrastructure Systems (Model Urban SysTems) – This project is designed to develop the theory that infrastructure systems, with their many interdependencies and complex adaptations, have many similarities to ecological systems. Insights will be useful in the future development of tools and methods for design and evaluation of urban infrastructure systems and their resilience under stresses such as climate change, urban growth patterns and extreme weather events.
Sponsor: National Science Foundation
Principal Investigator: John Crittenden
Southeastern Center for Air Pollution and Epidemiology (SCAPE) – A joint Emory University-Georgia Tech U.S. Environmental Protection Agency Clean Air Center studying air quality and the health effects of air pollution through four research projects.
Sponsor: U.S. Environmental Protection Agency
Principal Investigators: Armistead Russell, James Mulholland
SRN: Integrated Urban Infrastructure Solutions for Environmentally Sustainable, Health and Livable Cities – This National Science Foundation Sustainability Research Network is working to reimagine infrastructure — energy grids, road networks, green spaces, and food and water systems — to create cities that are highly functional, that promote the health of residents and the environment, and that have the intangible “vibe” that makes them desirable places to live and work.
Sponsor: National Science Foundation
Co-Principal Investigator: Armistead Russell
The Sustainable Development Footprint – Development of conceptual framework and analytical models to evaluate sustainable development progress.
Sponsors: National Science Foundation; U.S. Department of Transportation; Southeastern Transportation Research, Innovation, Development and Education Center
Principal Investigator: Adjo Amekudzi-Kennedy
Tools for Accurately Assessing the Influence of the Built Environment on Travel Behavior – Simple comparisons of travel behavior between those living in “urban” versus “suburban” environments are subject to the self-selection bias resulting from people sorting themselves into neighborhoods conducive to the way they prefer to travel in the first place. Those simple observed differences in behavior will not reflect the future outcome if people without such preferences are attracted into a neighborhood for other reasons, such as policy incentives. This ongoing project implements a number of different approaches to correcting for self-selection to produce more accurate assessments of the effectiveness of densifying and diversifying urban environments at leading to more sustainable travel patterns.
Sponsors: Various
Principal Investigator: Patricia Mokhtarian
Transportation Systems Health – Development of conceptual framework and analysis tools for characterizing transportation system health as a function of deficiency and growth needs.
Sponsor: Georgia Department of Transportation
Principal Investigators: Adjo Amekudzi-Kennedy, Michael Rodgers, Catherine Ross, Frank Southworth
Valuation of Investments in Building Energy Improvements under Uncertainties – The objectives of this project are to establish a long-term perspective in thinking about moving to sustainable buildings, enhance investment valuation of energy efficiency measures and renewable energy systems, and integrate quantified energy savings uncertainties in valuation.
Sponsor: National Science Foundation
Principal Investigator: Baabak Ashuri


Adjo A. Amekudzi-Kennedy
Associate Chair for Global Engineering Leadership and Entrepreneurship,...
Chloé Arson
Associate Professor
Baabak Ashuri
Joe Brown
External Adjunct Professor
Susan E. Burns
Associate Chair for Finance and Administration & Professor
John Crittenden
Director, Brook Byers Institute for Sustainable Systems, Hightower Chair...
Sheng Dai
Associate Professor & Group Coordinator
J. David Frost
Elizabeth and Bill Higginbotham Professor
Emily Grubert
Assistant Professor
Ching-Hua Huang
Turnipseed Family Chair & Professor
Kostas T. Konstantinidis
Richard C. Tucker Professor
Kimberly E. Kurtis
Associate Dean for Faculty Development and Scholarship & Professor
Patricia L. Mokhtarian
Clifford and William Greene, Jr. Professor
Spyros G. Pavlostathis
Professor Emeritus
Catherine Ross
Adjunct Professor
Armistead G. Russell
Howard T. Tellepsen Chair, Regents Professor & Group Coordinator
John E. Taylor
Associate Chair for Graduate Programs and Research Innovation &...
Yi-Chang James Tsai
Kari E. Watkins
Frederick Law Olmsted Associate Professor