This note proudly announces the 2020 Matthew G. Karlaftis Best Paper Award for the Journal of Infrastructure Systems. The Best Paper Award is presented on an annual basis as a tribute to the memory and in recognition of the contributions made by Professor Matthew G. Karlaftis of the National Technical University of Athens, Greece.The award selection committee was originally formed in April 2019, and consists of three associate editors of the journal. Upon review of the 66 papers, technical notes, and case studies published in the four issues within the 2020 calendar year, the committee selected for the award the technical paper “Design of a Multiperiod Tradable Credit Scheme under Vehicular Emissions Caps and Traveler Heterogeneity in Future Credit Price Perception,” coauthored by Mohammad Miralinaghi (Purdue University, West Lafayette, Indiana) and Srinivas Peeta (Georgia Institute of Technology, Atlanta) (Miralinaghi and Peeta 2020) for its novel pricing-based market-driven mechanism to manage vehicular emissions in an effort to achieve sustainability for urban transportation infrastructure.The authors were motivated by the need to reduce adverse environmental impacts related to vehicular emissions in metropolitan areas, while increasing the transportation system’s efficiency. To that end, they developed a novel pricing-based market-driven framework, and designed a system-optimal multiperiod tradable credit scheme for urban transportation infrastructure as a bilevel model. Within this bilevel model, the credit charging and allocation schemes are determined to minimize the total system travel time while meeting the emissions standards over each horizon period; and the multiperiod tradable credit scheme equilibrium condition is developed where system users decide on credit consumption and route choice in order to minimize their travel costs. An important contribution of the paper is the development of the system-optimal multiperiod tradable credit scheme, which allows central authorities to periodically meet their emission standards for metropolitan transportation infrastructure. The practical implications of the paper are also noteworthy. For example, the conducted numerical experiments reveal that the difference between travelers’ perceptions of future and actual credit prices is inversely related to the effectiveness of the proposed design in minimizing total system travel time, unless the design explicitly allows for this disparity. In addition, changes in emission standards are directly related to travel costs. The award selection committee is also pleased to note that the paper was very well motivated, the data and developed methods were presented in a concise and interesting manner, and the paper’s contributions and practical implications were clearly and interestingly articulated. These features of the paper were eminently illustrated through a number of informative figures and tables.The quality of the papers published in 2020 in the Journal of Infrastructure Systems was once again outstanding. For this reason, the award selection committee would like to honorably mention the technical paper “Real Option Valuation of Flexibility in Operation and Maintenance Contracts of Water Pipelines Based on Reliability Analysis,” coauthored by Mahdi Soltani (Islamic Azad University, Tehran, Iran) and Afshin Firouzi (Islamic Azad University, Tehran, Iran) (Soltani and Firouzi 2020), for its innovative application of a probabilistic reliability-based framework to model the extent of damage of corrosion-affected water pipelines.Matthew G. KarlaftisProfessor Karlaftis passed away unexpectedly in June 2014. He did extensive work in the areas of urban transportation, transportation planning and operations, and emergency response. He was a coauthor of an international best-selling book on transportation econometrics and statistics, two textbooks on transportation planning and public transportation, many book chapters, more than 100 publications in peer-reviewed journals, and many publications in conference proceedings, all highly cited worldwide. He participated in more than 45 national and European research projects as the principal or coprincipal investigator. He was deeply involved in editorial activities. He served as the editor in chief for Transportation Research Part C: Emerging Technologies, European editor of ASCE’s Journal of Transportation Engineering, associate editor of ASCE’s Journal of Infrastructure Systems, and an editorial board member for eight other journals. He was the recipient of the Fulbright Scholar Grant (2006–2007), the ASCE Walter L. Huber Civil Engineering Research Prize (2005), the TRB ABJ80 (now AED60) Committee on Statistical Methods Best Paper Award (2009), and the ASCE State-of-the-Art Paper Award (2011). He served on many technical committees and was a member of a variety of professional organizations and honor societies in Greece and the United States. He had a long association with the Hellenic Institute of Transportation Engineers, where he served as vice president (2010–2012) and president (2012–2014).References Miralinaghi, M., and S. Peeta. 2020. “Design of a multiperiod tradable credit scheme under vehicular emissions caps and traveler heterogeneity in future credit price perception.” J. Infrastruct. Syst. 26 (3): 04020030. https://doi.org/10.1061/(ASCE)IS.1943-555X.0000570. Soltani, M., and A. Firouzi. 2020. “Real option valuation of flexibility in operation and maintenance contracts of water pipelines based on reliability analysis.” J. Infrastruct. Syst. 26 (1): 04019031. https://doi.org/10.1061/(ASCE)IS.1943-555X.0000518.