After World War II, mass automobile production brought mass production of highways and low-density residential in far-flung suburbs of US cities. This resulted in trip origins far from destinations, causing traffic congestion, air pollution, and energy consumption at a high cost. Two scenarios were modeled: interconnected and hierarchical street networks. The former can accommodate mixed-use effectively, and the latter cannot. The result revealed significantly lower auto traffic, vehicle miles, and hours of travel in the grided roadway network. Reducing traffic is synonymous with making origins close to destinations which is made possible by grided roadways and mixed-use.
Keywords: interconnected roadway, grid, hierarchical roadway, mixed-use, connectivity, walkability
 Iravani, H & Rao, V. (2020). The effects of New Urbanism on public health, Journal of Urban Design, 25:2, 218-235, DOI: 10.1080/13574809.2018.1554997.
 Barrington-Leigh C and Millard-Ball A. 2015. A century of sprawl in the United States. Proceedings of the National Academy of Sciences of the United States of America (PNAS) 112 (27) 8244-8249, https://doi.org/10.1073/pnas.1504033112.
 Fishman, R. 1987. Bourgeois utopias: The rise and fall of suburbia. New York: Basic Books.
 Census, U. S. B. o. t. (1975). Historical statistics of the United States, colonial Times to 1970 (Series C-89-119). Washington, D.C.: U.S. Bureau of the Census.
 Dunphy, R. T. (1997). Moving Beyond Gridlock: Traffic and Development. Washington, D.C.: The Urban Land Institute.
 TRIP, A National Transportation Research Nonprofit (2021). America's Interstate Highway System at 65: Meeting America's Transportation Needs with a Reliable, Safe & Well-Maintained National Highway Network. Microsoft Word - TRIP_2021_Interstate_Report_FINAL_6-17-21.docx (tripnet.org)
 A Millard-Ball, L Schipper, Are we reaching peak travel? Trends in passenger transport in eight industrialized countries. Transport Reviews 31, 357-378 (2011).
 R Ewing, R Cervero, Travel and the built environment. Journal of the American Planning Association 76, 265-294 (2010).
 Calthorpe, P. (2018). TED2017. https://www.ted.com/talks/peter_calthorpe_7_principles_for_building_better_cities/transcript?language=en#t-94267.
 Lewyn M. (2001), Campaign of Sabotage: Big Government's War Against Public Transportation. Columbia Journal of Environmental Law. Vol. 26, Issue 259.
 Wikipedia. Pacific Electric. Retrieved on December 15, 2021.
 Evans F. (2021). How Interstate Highways Gutted Communities-and Reinforced Segregation. History Stories. https://www.history.com/news/interstate-highway-system-infrastructure-construction-segregation. Retrieved on December 15, 2021.
 Steyaert, J. (2012). Jane Jacobs, a Rebel with a Cause. Social Work and Society, Volume 10, Issue 1, 2012.
 Jacobs J. (1961), The Death and Life of Great American Cities.
 Story of Cities #32: Jane Jacobs v Robert Moses, battle of New York's urban titans. (2016). The Guardian. https://www.theguardian.com/cities/2016/apr/28/story-cities-32-new-york-jane-jacobs-robert-moses?CMP=soc_568.
 Iravani H., Anderson A., and Bevan A. (2018). Autonomous Vehicles: Rethinking Traffic Congestion Solutions in Cities. Journal of Geotechnical and Transportation Engineering. Volume 4, Issue 1.
 UBC Urban Design Studio. Chapter 3: An Interconnected Street System Interconnected street systems vs. dendritic street systems. http://www.urbanstudio.sala.ubc.ca/urbanstudio%202008/student%20materials/Chapter%203%20Draft%20Aug%208.pdf. Retrieved on December 15, 2021.
 Kulash W. (1990). Traditional Neighborhood Development: Will the Traffic Work? 11th Annual Pedestrian Conference in Bellevue, WA.
 Caliper Corporation. 2021. Travel Demand Modeling with TransCAD 9. Newton, MA. September 3, 2021. www.caliper.com.
Geotechnical projects generally consume large quantities of resources and energy and release considerable amounts of CO2 in the atmosphere, and therefore, have a significant impact on the environment. To minimize this effect, sustainable solutions and materials have been proposed and adopted in the literature and practice as alternatives to conventional methods wherever applicable. This study reviews and discusses sustainability in geotechnical engineering, in particular, three ground improvement techniques including deep soil mixing (DSM), dynamic compaction, and vibro replacement (VR) compared to the piling method. Some eco-friendly recommendations are proposed to mitigate the environmental loads of the discussed ground improvement techniques. Moreover, carbon footprints of three case study projects, each with three alternative solutions (i.e., piling, DSM, and VR), are assessed and compared in two conditions, namely, with and without eco-friendly measures (i.e., substituting new materials with recycled or recovered construction materials or with the by-products of other industries). In the studied cases, the CO2 discharge amounts of DSM and VR were found to be around half and one-tenth of that amount in piling. The CO2 emissions of all three products showed a significant decrease when adopting the eco-measures, averagely, 34, 60, and 14% for piling, DSM, and VR, respectively. Finally, the CO2 emissions of the above cases are presented in functional units.
Keywords: Carbon Footprint, Sustainability, Ground Improvement, Piling, DSM, VR
 R. M. Andrew, "Global CO2 Emissions from Cement Production, 1928-2017". Earth System Science Data 10, no. 4 (December 10): pp. 2213-2239, 2018, http://dx.doi.org/10.5194/essd-10-2213-2018
 D. Basu & A. J. Puppala, "Sustainability: an emerging discipline within geotechnical engineering" in 16th European Conference on Soil Mechanics and Geotechnical Engineering, Geotechnical Engineering for Infrastructure and Development, 2015, pp. 2487-2492, http://10.1680/ecsmge.60678
 D. Basu, A. Misra & A. J. Puppala, "Sustainability and Geotechnical Engineering: Perspectives and Review" Canadian Geotechnical Journal 52, no. 1, pp. 96-113, Jan. 2015. http://dx.doi.org/10.1139/cgj-2013-0120
 I. Chang, J. Im & G. -C. Cho, "Introduction of Microbial Biopolymers in Soil Treatment for Future Environmentally-Friendly and Sustainable Geotechnical Engineering" Sustainability 8, no. 3, 251, Mar. 2016, http://dx.doi.org/10.3390/su8030251
 I. Chang, M. Lee & G. -C. Cho, "Global CO2 Emission-Related Geotechnical Engineering Hazards and the Mission for Sustainable Geotechnical Engineering" Energies 12, no. 13, 2567, Jul. 2019, http://dx.doi.org/10.3390/en12132567
 B. Chittoori, A. J. Puppala, R. Reddy & D. Marshall, "Sustainable Reutilization of Excavated Trench Material" in GeoCongress 2012. American Society of Civil Engineers, http://dx.doi.org/10.1061/9780784412121.440
 B. Clarke, (2010). "Briefing: Carbon Critical Design. Proceedings of the Institution of Civil Engineers" Engineering Sustainability 163, no. 2, pp. 57-59, Jun. 2010, http://dx.doi.org/10.1680/ensu.2010.163.2.57
 M. K. Dixit, J. L. Fernández-Solís, S. Lavy & C. H. Culp, "Identification of Parameters for Embodied Energy Measurement: A Literature Review" Energy and Buildings 42, no. 8, pp. 1238-1247, Aug. 2010, http://dx.doi.org/10.1016/j.enbuild.2010.02.016.
 E. Dlugokencky & P. Tans, "National Oceanic & Atmospheric Administraion (NOAA)" Earth System Research Laboratory (ESRL). Available online: www.esrl.noaa.gov/gmd/ccgg/trends/
 D. Egan & B. C. Slocombe, "Demonstrating Environmental Benefits of Ground Improvement" in Proceedings of the Institution of Civil Engineers - Ground Improvement 163, no. 1, Feb. 2010, pp. 63-69, http://dx.doi.org/10.1680/grim.2010.163.1.63
 Environment Agency (UK), Environment Agency Carbon Calculator, www.environment-agency.gov.uk.
 US EPA (United States Environmental Protection Agency), Life cycle assessment: Principles and practice, Rep. No. EPA/600/R-06/060, National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, 2006.
 FHWA, Federal Highway Administration Design Manual: Deep Mixing for Embankment and Foundation, Support Publication No. FHWA-HRT-13-046. 2013
 R. J. Fragaszy, J. C. Santamarina, A. Amekudzi, D. Assimaki, R. Bachus, S. E. Burns & M. Cha, "Sustainable Development and Energy Geotechnology Potential Roles for Geotechnical Engineering" KSCE Journal of Civil Engineering 15, no. 4, pp. 611-621, Apr. 2011, http://dx.doi.org/10.1007/s12205-011-0102-7.
 M. J. Goedkoop, R. Heijungs, M. Huijbregts, A. De Schryver, J. Struijs & R. van Zelm, "ReCiPe 2008. A Life Cycle Impact Assessment Method which Comprises Harmonised Category Indicators at the Midpoint and the Endpoint Level", Report I: Characterisation. Den Haag, Netherlands, 2008.
 A. Gomes Correia, M. G. Winter & A. J. Puppala, "A Review of Sustainable Approaches in Transport Infrastructure Geotechnics" Transportation Geotechnics 7, pp. 21-28, Jun. 2016, http://dx.doi.org/10.1016/j.trgeo.2016.03.003
 G. Hammond & C. I. Jones, Inventory of Carbon and Energy (ICE), Version 1.6a, 2008,University of Bath, 2008, http://www.bath.a.c.uk/mech-eng/semt/embodied/
 G. Hammond & C. I. Jones, Inventory of carbon and energy (ICE), version 2.0, Sustainable Energy Research Team (SERT), 2011, Univ. of Bath, Bath, U.K.
 D. G. A. Holt, "Sustainable assessment for geotechnical projects", Ph.D. thesis, University of Birmingham, UK, 2011.
 D. G. A. Holt, I. Jefferson, P. A. Braithwaite & D. N. Chapman, "Embedding Sustainability into Geotechnics. Part A: Methodology" in Proceedings of the Institution of Civil Engineers - Engineering Sustainability 163, no. 3, Sep. 2010, pp. 127-135, http://dx.doi.org/10.1680/ensu.2010.163.3.127
 M. A. J. Huijbregts, Z. J. N. Steinmann, P. M. F. Elshout, G. Stam, F. Verones, M. Vieira, M. Zijp, A. Hollander & R. van Zelm, "ReCiPe2016: A Harmonised Life Cycle Impact Assessment Method at Midpoint and Endpoint Level" The International Journal of Life Cycle Assessment 22, no. 2, pp. 138-147, Dec. 2012, http://dx.doi.org/10.1007/s11367-016-1246-y
 M. A. J. Huijbregts, Z. J. N. Steinmann, P. M. F. Elshout, G. Stam, F. Verones, M. Vieira, M. Zijp, A. Hollander & R. van Zelm, "Correction to: ReCiPe2016: A Harmonised Life Cycle Impact Assessment Method at Midpoint and Endpoint Level" The International Journal of Life Cycle Assessment 25, no. 8, pp. 1635-1635, Jul. 2020, http://dx.doi.org/10.1007/s11367-020-01761-5
 T. Inui, C. Chau, K. Soga, D. Nicolson & N. O'Riordan, "Embodied Energy and Gas Emissions of Retaining Wall Structures" Journal of Geotechnical and Geoenvironmental Engineering 137, no. 10, pp. 958-967, Oct. 2011, http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0000507
 ISO (International Organization for Standardization), Environmental management - Life cycle assessment - Principles and framework. ISO 14040, Geneva, 2006.
 I. Jefferson, M. Gaterell, A. M. Thomas & C. J. Serridge, "Emissions Assessment Related to Vibro Stone Columns" in Proceedings of the Institution of Civil Engineers - Ground Improvement 163, no. 1, Feb. 2010, pp. 71-77, http://dx.doi.org/10.1680/grim.2010.163.1.71
 C. J. Kibert, "Sustainable construction" 2nd ed. John Wiley and Sons Inc., New Jersey, 2008.
 K. Kirsch & F. Bell, "Ground Improvement" CRC Press. ISBN 9780367865696, 2013.
 K. Kirsch & F. Kirsch, "Ground Improvement by Deep Vibratory Methods: Spon Press, Abingdon, Oxfordshire, UK. ISBN 9780367139025, 2010.
 B. Lemaignan & J. Y. Wilmotte, "EFFC DFI carbon calculator methodological & user guide v2.1", EFFC-DFI, 2013.
 A. Misra & D. Basu, "Sustainability metrics for pile foundations" Indian Geotechnical Journal, 41(2), pp. 108-120, 2011.
 R. K. Pachauri, M. R. Allen, V. R. Barros, J. Broome, W. Cramer, R. Christ, J. A. Church, L. Clarke, Q. Dahe & P. Dasgupta, "Climate Change 2014" Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change; Intergovernmental Panel on Climate Change (IPCC): Geneva, Switzerland, 2014, p. 151.
 S. Parkin, "Sustainable Development: The Concept and the Practical Challenge" in Proceedings of the Institution of Civil Engineers - Civil Engineering 138, no. 6, Nov. 2000, pp. 3-8. http://dx.doi.org/10.1680/cien.2000.138.6.3
 A. R. Pearce, Y. H. Ahn & HanmiGlobal Co Ltd., "Sustainable buildings and infrastructure: Paths to the future, Routledge", New York. ISBN 9781138672253, 2012.
 PRe Consultants B.V., SimaPro software, v.8.0.2. Amersfoort. Utrecht, Netherlands, 2010. www.pre-sustainability.com
 A. J. Raymond, M. A. Pinkse, A. Kendall & J. T. DeJong, "Life-Cycle Assessment of Ground Improvement Alternatives for the Treasure Island, California, Redevelopment" In Geotechnical Frontiers, 2017, American Society of Civil Engineers. http://dx.doi.org/10.1061/9780784480434.037
 H. Rodhe, "A Comparison of the Contribution of Various Gases to the Greenhouse Effect" Science 248, no. 4960, pp. 1217-1219, Jun. 1990, http://dx.doi.org/10.1126/science.248.4960.1217
 S. H. Schneider, "The Greenhouse Effect: Science and Policy" Science 243, no. 4892, pp. 771-781, Feb. 1989, http://dx.doi.org/10.1126/science.243.4892.771
 C. J. Serridge, "Achieving Sustainability in Vibro Stone Column Techniques" in Proceedings of the Institution of Civil Engineers - Engineering Sustainability 158, no. 4, Dec. 2005, pp. 211-222. http://dx.doi.org/10.1680/ensu.2005.158.4.211
 C. M. Shillaber, J. K. Mitchell & J. E. Dove, "Energy and Carbon Assessment of Ground Improvement Works. I: Definitions and Background" Journal of Geotechnical and Geoenvironmental Engineering 142, no. 3, Mar 2016a, 04015083. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0001410
 C. M. Shillaber, J. K. Mitchell & J. E. Dove, "Energy and Carbon Assessment of Ground Improvement Works. II: Working Model and Example" Journal of Geotechnical and Geoenvironmental Engineering 142, no. 3, Mar 2016b, 04015084. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0001411
 H. Soleimani Fard, M. Nagi, A. Ashmawy & E. Saqan, "Behavior of DSM in Calcareous Sand in the UAE and the Middle East" in Soil Mixing Conference, DFI, 2021, Gdansk, Poland.
 C. Spaulding, M. Masse & J. LaBrozzi, "Ground improvement technologies for a sustainable world" in GeoCongress: Geosustainability and Geohazard Mitigation, 2008 (GSP 178). ISBN: 978-0-7844-0971-8
 M. Topolnicki, "Geotechnical design and performance of road and railway viaducts supported on DSM columns - a summary of practice" in International Conference on Deep Mixing, Jun. 2015, pp. 1-20, San Francisco, USA.
 M. Topolnicki, "General overview and advances in Deep Soil Mixing" in XXIV Geotechnical Conference of Torino Design, Construction and Controls of Soil Improvement Systems, 2016, pp. 1-30, Torino, Italy, 25-26.02.2016.
 United States Geological Survey (USGS). Cement Statistics and Information. Available online: www.usgs.gov/centers/nmic/cement-statistics-and-information
 W. v. Wintzingerode, A. Zohrer, A. Bell & Q. Gisselmann, "Calculations on Greenhouse Gas Emissions from Geotechnical Construction Processes" Geotechnik 34, no. 3, pp. 218-221, Sep. 2011, http://dx.doi.org/10.1002/gete.201100010
 M. K. van Aalst, "The Impacts of Climate Change on the Risk of Natural Disasters" Disasters 30, no. 1, pp. 5-18, Mar. 2006, http://dx.doi.org/10.1111/j.1467-9523.2006.00303.x
 L. Vukotic, R. A. Fenner & K. Symons, "Assessing Embodied Energy of Building Structural Elements" in Proceedings of the Institution of Civil Engineers - Engineering Sustainability 163, no. 3, Sep. 2010, pp. 147-158, http://dx.doi.org/10.1680/ensu.2010.163.3.147
 A. Zohrer, J. Wehr & M. Stelle, "Is Ground Improvement Environmental Friendly? Ecological Balance of Foundation Engineering Methods", in EFFC-DFI conference, Jan. 2010, London.