The Optic report “Inventory of tools and methods for early detection of adverse effects” addresses this and recommends a mix of quantitative and qualitative assessment approaches to policy making, because all effects of transport policy – intended or unintended – may be anticipated before the policy is implemented.
Potential supplementary measures can therefore be planned at the same time as the main policy measure when addressing undesirable outcomes or increasing acceptability for controversial measures.
The report describes in detail the different appraisal techniques – quantitative as well as qualitative – available for evaluation of transport policies. In particular it focuses on the possibilities and limitations offered by the EU wide models TransTools (Tools for Transport forecasting and Scenario testing) and Tremove.
TransTools is a transport demand and network model covering both freight (including intermodal transport) and passenger transport. Tremove is a transport and emission model used to assess the impact of single environmental policies and policy packages on European level.
The report recommends when and how approaches of quantitative and qualitative character should be used and discusses the particular challenges of transport policy packages in which a bundle of measures is implemented together in order to meet one or more policy objectives. Structural closed methods (mainly quantitative) should be applied to quantify as much as possible of the expected effects. This phase is dominated by experts and application of models such as TransTools and Tremove.
The report gives examples of complex policy-making processes and of how unintended effects can be evaluated and identified in advance. For instance, in 2009 the German government introduced a 2,500 Euro bonus when a new car was purchased and the old one handed in for scrappage. The measure was intended to stimulate car manufacturing in Germany at a time of economic downturn and to reduce the stock of high emission cars in the country.
These intended effects could be reproduced with a transport model (TREMOVE), but any unintended effect of scrapped cars being exported to other countries would not be covered by the model. This example showed that models can only partially reveal the entire complexity of cause-effect relations. In these cases the report recommends that additional, so-called structurally open, methods be applied at an early stage (mainly qualitative) in order to point to effects not covered by the models.
Another example is subsidies for the purchase of electric vehicles. The shift to more electric vehicles would not be reflected in the TransTools model, but the effect of the policy (reduced emissions) could be assessed ex-post by applying the impact model Tremove.
However, possibly unintended effects as more mileages due to reduced fuel costs, would require to be specifically addressed in the model, for instance by considering different car types, issue normally not treated in this type of model.
The demand for electric energy and new power plants would be out of the scope of the model because the effect occurs in the energy sector.
These kinds of effects require structurally open approaches to be detected or even the application of other models when effects appear outside the transport domain.
To identify different effects, the report recommends using structurally open methods in an explorative phase at the beginning of the policymaking process. Mainly qualitative elements such as a stakeholder consultation play an important role here and could be accompanied by simple pre-structured approaches (e.g. CBA) to support the exclusion of unrealistic options, or by explorative scenarios to cover different future developments.
In the second stage of policy package analysis, the project recommends that structurally closed methods be conducted and generally applied by analysts and experts in the field. Given the results obtained, the policy-packaging process should again be opened up and the results reflected on considering potentially affected stakeholders.
Download deliverable 2:
Inventory of tools and methods for early detection of adverse effects.