Investigation on the Use of Urban Road Pricing as a Road Safety Intervention: A Discrete Choice Experiment

<p><span>Background.</span></p> <p><span>Urban road pricing has traditionally been justified as a congestion-management instrument. However, road crashes represent a major external cost of transport systems, and safety has rarely been explicitly integrated into pricing design or appraisal. This study examines whether road pricing framed as a road safety intervention generates behavioural shifts that are equal to or greater than those produced by conventional congestion-oriented pricing.</span></p> <p><span>Methods.</span></p> <p><span>A two-arm parallel randomised controlled discrete choice experiment (N = 600) was conducted, comparing congestion-framed (RP) and safety-framed (RS) pricing across three behavioural domains: mode choice, route choice, and time of departure. Mixed logit (hierarchical Bayes) models were estimated to capture preference heterogeneity. Predicted probabilities, behavioural shifts, and arc elasticities were computed for ten counterfactual pricing scenarios. Safety impacts were translated into avoided fatalities using national vehicle-kilometre fatality rates under three stylised implementation scales.</span></p> <p><span>Results.</span></p> <p><span>Behavioural responsiveness follows a consistent hierarchy across frames: route choice is the most elastic adjustment margin, followed by departure-time shifting, while modal substitution is comparatively constrained. Safety framing systematically amplifies behavioural shifts, particularly in competitive trade-off scenarios, but does not alter the structural ordering of adjustment mechanisms. Counterfactual simulations indicate that safety-oriented pricing produces 50–70% larger estimated reductions in fatalities relative to congestion-oriented pricing under equivalent coverage assumptions. Moderate-scale scenarios yield magnitudes broadly consistent with empirical safety outcomes observed in existing pricing schemes.</span></p> <p><span>Conclusions.</span></p> <p><span>Road pricing operates primarily through within-mode spatial and temporal reallocation rather than wholesale modal substitution. Nevertheless, behavioural evidence indicates that crash risk can be internalised through pricing design and framing. The findings suggest that road pricing should be conceptualised as a multi-externality governance instrument capable of addressing both congestion and road trauma, with safety integration representing a policy opportunity rather than a behavioural constraint.</span></p>