When There Is No “Best” Solution: Decision-Making Conundrums in Istanbul's Urban Mobility

Abstract

Urban mobility policymaking is often framed as a search for optimal solutions to problems such as traffic congestion, inadequate public transport capacity, and unsustainable travel patterns. In practice, however, policymakers rarely operate in decision environments where a single solution can simultaneously satisfy all relevant objectives. Instead, urban mobility decisions involve competing priorities, uncertain outcomes, institutional constraints, and conflicting interests among different groups of transport users. This paper examines these challenges through the case of Istanbul, a megacity characterised by rapidly changing travel demand, extensive public transport networks, persistent congestion, and strong dependence on road-based mobility. Rather than evaluating a particular intervention numerically, the paper identifies and analyses a set of key policy dilemmas confronting urban mobility policymakers in Istanbul. These include the allocation of scarce road space between private and public transport, congestion relief versus sustainable mobility, large-scale infrastructure investment versus incremental interventions, system efficiency versus social equity, evidence-based policy versus political and institutional feasibility, and short-term improvements versus long-term transformation. The paper argues that these dilemmas should not be understood simply as failures to identify a technically optimal solution. Rather, they represent inherent characteristics of complex urban mobility decision-making, in which policy alternatives generate different combinations of benefits, costs, risks, and distributional consequences. Drawing on the Istanbul case, the paper develops a conceptual framework for understanding urban mobility policymaking as a process of making informed choices among imperfect alternatives under competing objectives and uncertainty. The framework highlights the importance of explicitly recognising trade-offs and decision contexts when designing and evaluating urban mobility policies.