دانلود رایگان مقاله پیامدهای رفتاری اثرات غیر خطی در سیاست های حمل و نقل باری شهری

Abstract

Cities import goods and freight transport is essential. However, it also generates social costs. Ensuring efficient urban freight transport is important although difficult. Policy makers intervene by defining and implementing policy measures that try to foster market efficiency in an environmentally sustainable way. General-purpose policies have often backfired when insufficient attention was paid to specific stakeholders’ preferences. This paper investigates the impact the number of loading and unloading bays, the probability of finding them free and entrance fees have on retailers’ and transport providers’ utilities. Willingness to pay measures are used to test and quantify possible non-linear attribute variation effects. The main findings underline both the substantial difference in retailers’ and transport providers’ utility while evidencing the presence of non-negligible non-linear effects. Unfortunately the research results obtained are at odds with the recently introduced changes of the regulatory framework governing the Limited Traffic Zone in the city of Rome that is the case study considered in the paper.

5. Concluding remarks

This paper tests the non-linear effects of level variation for the attributes considered in a urban freight policy for the Limited Traffic Zone in Rome. The research focused on retailers’ and transport providers’ preferences eliciting them via a Stated Ranking Exercise. The results obtained indicate that, for the sample interviewed, nonlinear effects are more relevant for retailers with respect to transport providers. The bias introduced if non-linear effects are neglected increases with the distance the variation has with respect to the status quo. The paper contributes to the literature by underlining the potential impact of a phenomenon not usually considered relevant. The analysis is performed at an agent-specific level. Whereas in this case the non-linear effects alone are considered, previous research from the authors indicates that heterogeneity in preferences can be present also within single agent category. Future research will aim at: (1) increasing the number of respondents, (2) widening the type of policy instruments evaluated, (3) include other relevant stakeholders (i.e. citizens). Unfortunately, notwithstanding the detailed and cautionary suggestions provided, local decision makers in Rome have recently modified the regulatory framework by substantially increase the entrance fee in the Limited Traffic Zone without any compensatory measures. The decision taken does not bode well for the future. The upheaval it has provoked suggests that this policy intervention was considered as yet another form of additional taxation. This is not in line with the consultative approach adopted in other large cities with similar problems (e.g. Lindholm and Browne, 2013).