آیا افراد دارای ترجیحات مختلف به عنوان مصرف کننده و شهروند هستند؟ تجارت بین زمان سفر و ایمنی

Transport policy decisions often involve a trade-off between travel time and safety. Transport economists generally evaluate the societal value of transport policy options involving travel time versus safety trade-offs in a Cost-Benefit Analysis (CBA) through multiplying the expected change in traffic casualties with the value of a statistical life (VOSL) and multiplying the changes in travel time with the (marginal) value of time (VOT). The dominant empirical approach to infer the VOSL and the VOT is based on stated preference experiments in which respondents are asked to make choices between (hypothetical) routes which differ in terms of various characteristics (e.g. travel time and number of fatal accidents per year). This approach towards inferring the VOT and the VOSL has been criticized by scholars who argue that individuals’ preferences as consumer of mobility inferred through (hypothetical) route choices may be a poor proxy for how the same individuals in their role of citizen believe that government should trade-off safety and travel time. This study investigates the extent to which individuals indeed do have different preferences as consumer and citizen when trading off travel time and safety, by conducting five stated choice experiments in which respondents are asked to choose between hypothetical routes as consumer or hypothetical routes/policy options as citizen. Our results suggest that individuals in their role as citizen assign substantially more value to safety than travel time when compared to their consumer choices. We believe that this paper could fuel a debate about whether or not the VOT and VOSL inferred from choices individuals make as a car driver are the single most relevant metrics for the valuation of expected changes in traffic casualties and travel time in the appraisal of transport-related government policy options.