Uncertainties of Domestic Road Freight Statistics: Insights for Regional Material Flow Studies

Abstract

Freight statistics are at the core of many studies in the field of industrial ecology because they depict the physical inter-dependencies of territories and allow to link worldwide productions and consumptions. Recent studies have been increasingly focusing on subnational scales, often relying on domestic freight data. In this perspective, this article analyses the uncertainties of the French domestic road freight survey, road being by far the most common mode of transport in the country. Based on a statistical analysis of the survey, we propose a model to estimate the uncertainty of any given domestic road transport flow. We also assess uncertainty reduction when averaging the flows over several years, and obtain for instance a 30% reduction for a 3-year average. We then study the impact of the uncertainties on regional material flow studies such as the Economy-Wide Material Flow Analysis of the Bourgogne region. Overall the case studies advocate for a systematic assessment of freight uncertainties, as neither the disaggregation level nor the quantities traded are good enough predictors. This justifies the need for an easy-to-implement estimation model. Finally, basic comparison with the German and Swedish surveys tend to indicate that the main conclusions presented in this article are likely to be valid in other European countries.

Using Constraints in Freight Volume to Identify Regional Needs for Roadway Infrastructure

“…To justify the infrastructure investments, both transport models and economic models are used to evaluate the interactions among production and consumption, often on a subnational level. Courtonne et al [13] modelled and estimated indeterminateness of domestic shipping flows in France. Alina [14] analysed the usage of the speed-flow curve in traffic modelling.…”

Assessing resource consumption at the subnational level: A novel accounting method based on provincial selected material consumption

“…Niza, Rosado, and Ferrão (2009) conducted an analysis in Lisbon and estimated IM and EX by using national freight transport statistics that ignores goods of less than 3 ton capacity; in the case of London, Horta and Keirstead (2017) downscaled aggregate energy consumption to local districts by using six models. However, uncertainties (Courtonne et al., 2018; Laner et al., 2014; ) in both underlying data and estimation methods are likely to pile up, adding to the deviation of the outcome. Moreover, not all regions report statistics supporting the above studies, and physical trade data are preferred rather than monetary data to facilitate MFA.…”

Métabolisme associé aux systèmes agri-alimentaires : enjeux et diversité d’approches dans la communauté de recherche française

“…Comment déploie-t-elle ce type d'approche des SAA ? Des travaux ont déjà soulevé les questions de délimitation des systèmes (Barles, 2009 ;Petit, 2021) et sous-systèmes (Kleinpeter et al, 2022), ou les difficultés à quantifier les flux (Vigne et al, 2012 ;Courtonne et al, 2018 ;Grillot et al, 2021). Aussi proposons-nous une revue des travaux sur le métabolisme social des SAA dans la communauté de recherche française, afin d'expliciter les enjeux et les dimensions d'analyse du métabolisme social, visant à éclairer les choix de transformation des SAA.…”