CO2 emissions from road transport represent an important part of the overall greenhouse gas emissions and consequently contribute to the on-going climate change. Efforts to reduce those emissions need to consider all influencing factors on energy consumption of road vehicles, which is directly linked to their carbon footprint. Besides the ‘greening’ of vehicle technologies the improvement of road infrastructure characteristics related to fuel consumption can contribute to an overall CO2 reduction in road transport. This requires both a thorough understanding of those interactions and the implementation of results in current pavement and asset management practice. In contributing to both objectives MIRAVEC enables National Road Administrations (NRAs) to effectively support the reduction of road transport greenhouse gas emissions.
While some previous and on-going projects like ECRPD or MIRIAM focused on specific topics in this area, the objective of MIRAVEC is to build on existing knowledge and models. In doing so MIRAVEC aims at achieving a more holistic view considering a broad variety of effects (e.g. the interaction between road design and traffic flow). Moreover, MIRAVEC will investigate the capabilities of available models and tools and evaluate the relative importance of different road infrastructure characteristics for different settings (e.g. topography or network type). The relationship with road safety and noise emissions will be examined. The project results will be compiled into recommendations to NRAs on how to implement the findings, models and tools in pavement and asset management systems. The dissemination to the NRAs is planned by using workshops, project presentations and a project website.
MIRAVEC achieves its objectives through the following project activities:
- Work Package 1 (WP1) will identify the most important effects contributing to road vehicle energy consumption which are governed by interaction with the infrastructure and their associated parameters. This work package will create a compilation of effects and parameters which will serve as a basis for Work Package 2 and 3.
- Work Package 2 (WP2) will evaluate the necessary modelling tools for the effects defined in WP1. This will include the currently available tools and their capabilities, further developments to improve their performance and scope, the possibilities for integration of different tools and the remaining gaps.
- Work Package 3 (WP3) will consider and assess the relative importance of the effects defined in WP1 in different contexts and settings and will evaluate the potential savings in vehicle energy use that could be achieved by NRAs by making changes to the road infrastructure. WP3 will also consider the effects of changing vehicle fleets, including greater uptake of electric vehicles on the estimated savings.
- Work Package 4 (WP4) will build upon the output of WPs1-3. Its first task is to investigate the current role of road vehicle energy consumption in road pavement and asset management systems. Based on this it will make specific recommendations how to implement the available knowledge and/or models. This will support energy efficiency considerations in the decision making processes of NRAs while also maintaining high levels of safety and low noise emissions.
- Work Package 5 (WP5) will effectively disseminate MIRAVEC’s results to the NRAs and manage the overall project.
The main findings and recommendations of the project can be summarised as follows:
- Five major groups of parameters influencing road vehicle energy and fuel consumption were identified, of which a subset was selected based on impact, potential for influence by NRAs and integration into existing fuel consumption models. Further analysis showed that while currently monitored parameters can be used for modelling several effects of the infrastructure influence, knowledge gaps remain with respect to other parameters and the correct modelling of associated effects.
- There is no current model which takes all infrastructure-related effects into account. Most models for fuel consumption and CO2 emission of road vehicles focus on vehicle and traffic flow characteristics and tend to neglect details of the infrastructure. The Swedish VETO model is one of the most advanced models in this respect and was the basis of many analyses. As the knowledge about the infrastructure influence increases, these models offer the possibility to integrate this knowledge into decision making.
- The spreadsheet tool developed in WP3 allows the comparison of the effects of different infrastructure-related measures on fuel consumption and CO2 emission. It requires data about the most widely available pavement and road layout parameters and uses information about traffic flow and vehicles as background information. While the tool can be applied even with limited data, the strong influence of these background data found in the analysis may supersede the infrastructure effects in some cases.
- The investigation of the current situation with regard to the occurrence of this topic in pavement and asset management found a growing awareness of its importance with road managers, but so far very limited implementation in the actual systems. While future models based on the more commonly monitored infrastructure parameters will make the integration of vehicle CO2 emission feasible, acceptance and weight in decision making in the view of limited financial resources for maintenance still remain to be achieved.