Sustainable Growth of Cybersecurity for Smart Autonomous Vehicle Networks: The TARA Methodology

In the context of population growth, pressure on finite resources, and the limits of the current urban transport model, sustainable mobility in smart cities has become a strategic priority. Connected and automated vehicles (CAVs) and intelligent networks (V2X, IoV) promise reductions in consumption, emissions, and congestion, yet they introduce an unprecedented cyber-attack surface, with impacts on safety, privacy, and operational continuity. The ISO/SAE 21434 standard and UNECE R155 regulations mandate systematic Threat Analysis and Risk Assessment (TARA) throughout the system lifecycle. This article proposes a sustainability-oriented approach to cybersecurity, in which TARA is treated not only as a compliance instrument but as an iterative, adaptive, and resource-efficient methodology capable of supporting intelligent autonomous vehicle networks over the long term without eroding the gains of sustainable mobility. The TARA steps according to ISO/SAE 21434 are detailed, the specificities of application to autonomous vehicle networks (SAE levels L3–L5) in smart cities are analyzed, elements of TARA 2.0 are introduced, and integration with sustainability principles is discussed, considering the limits to growth and consumption constraints. The article includes a complete case study on an SAE Level 4 autonomous driving system (Urban Shuttle L4), comparative tables of TARA 1.0 vs. TARA 2.0, numerical examples of risk calculation, risk matrices, detailed asset and threat lists, and a proposal for cybersecurity sustainability metrics.