A general theory of shared-mobility impacts: Theory-finalization, measurement-methods, and empirical field-tests

• Applicant: Dr. Jörg Firnkorn
• Subject Area: City Planning, Spatial Planning, Transportation and Infrastructure Planning, Landscape Planning
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 231567560

Carsharing systems may aggravate or solve traffic-related problems in cities, depending on many details. Recent studies on traditional station-based carsharing-systems found that the majority of all carsharing users increase their total kilometers travelled in passenger cars through carsharing usage. In addition, since 2009 there are new one-way carsharing-systems in operation for which there have been hardly any impact analyses so far. Given the general lack of empirical studies for all carsharing system-types, the detailed impacts of different carsharing systems on cities are still unknown. But the results of impact analyses depend strongly on the applied measurement-methodology. So far there has been no single research design of an empirical carsharing-study which would have been replicated once (as of May 2012). Because of this, the comparability of previous studies is limited. For example, results change considerably if co-drivers are included in calculations of emission-impacts or not. Also, if for example the possible reduction of the aggregated need for parking spaces is calculated, resulting from a possible reduction of private vehicle holding as a reaction to carsharing schemes, the results may even get reversed if a statistical control group (non-carsharing users) is used (or not). Therefore, a standardized measurement-method for the quantification of the impacts of different carsharing systems on cities is necessary, in order to enable a comparability of empirical findings. This DFG-proposal suggests a research project comprising the development of a standardized measurement-method for the quantification of the impacts of different carsharing systems on cities, and the methodology-application to different carsharing system-types (station-based and one-way). The proposed project has three central goals:1.) Development of a standardized measurement-method for the quantification of the impacts of different carsharing systems on cities2.) Application of the developed measurement-method to two different carsharing system-types, a station-based and a one-way carsharing-system3.) Comparison of the impacts. Given that the identical (standardized) measurement-method would be applied to both systems, for the first time the (possibly found) different effects could be linked to the different system functionalities A standardized measurement-method for the quantification of the impacts of different carsharing systems on cities has not been discussed by a previous publication (as of May 2012). Also, there has been no previous empirical study comparing the effects of station-based and one-way carsharing systems. The results of the proposed DFG-project would support city planners in allocating limited resources systematically to different carsharing system-types.

• DFG Programme: Research Fellowships
• International Connection: USA
• Participating Institution: University of California, Berkeley ; Transportation Sustainability Research Center
• Host: Professorin Susan Shaheen, Ph.D.