The Executive Secretary of the Northern Corridor Transit and Transport Coordination Authority (NCTTCA) is responsible mainly for monitoring the implementation of the decisions taken by the Northern Corridor Policy Organs, ensure the overall functions and operations of the NCTTCA, strategic planning and resource mobilisation, among others are meticulously achieved.

Dr. Eng. John Deng Diar Diing is an infrastructure development expert and leader with a diverse background in project management, public policy, and environmental assessment. He holds a PhD in Project Planning and Management from the University of Nairobi, a Master of Public Administration from Harvard University, where he was a distinguished Edward S. Mason Fellow, and an MSc in Management of Projects (Construction) from the University of Manchester.

Prior to ascending to the helm of the NCTTCA, Dr. John was the Deputy Director of Infrastructure Development and Management at the Northern Corridor Transit & Transport Coordination Authority (NCTTCA) Secretariat in Mombasa, Kenya.

He also served as the Director for Projects for South Sudan Roads Authority where he was instrumental in managing strategic road development projects. Additionally, Dr. John served as Managing Director of Horizon Real Estate Construction Company Ltd, overseeing significant construction projects in South Sudan.

Dr. John has a strong foundation in organizational strategy, stakeholder management, and leadership. He has been recognized for his contributions to the field with several prestigious awards and fellowships, including the Eric Yankah Award from Harvard Kennedy School and a Chevening Scholarship.