Background: Denmark is the pioneering nation in reducing the rolling resistance (RR) between tire and road by optimizing road surfaces. Tire companies have come far by optimizing tires and many data are available for the effect of road texture on RR, but the Innovation Fund project COOEE (2011-2015) was the first to demonstrate that RR can be reduced by optimized pavements. Thus a 5% reduction of passenger-car energy consumption has recently been validated for the best test roads. The durability of the new generation of pavements needs to be further investigated and validated, however, before they can be implemented; moreover, even higher energy savings are likely obtainable.

Objectives: By reducing the RR ROSE (2016-2018) aims at designing a durable asphalt pavement with at least 6.5% reduction of passenger-car energy consumption compared to that of average present Danish roads.

Means: To achieve uniquely low RR properties one needs reliable mathematical models that answer the following two questions: 1) For a given surface and tire, what are the RR and the skid resistance? 2) For a given asphalt mix design and road construction method, what are the resulting road-surface texture and the road’s durability? As input to the first of these models, ROSE constructs a scaled-down “model- validation” laboratory for simultaneous measurements of RR and skid resistance, the first of its kind.

Success criteria: ROSE aims at resulting in a new and improved generation of asphalt pavements with at least a 6.5% lower RR than that of average present Danish roads. A further success criterion is that the ROSE results are implemented into the Danish Road Directorate’s asset-management system.

Value creation: ROSE involves all three parts of the value chain: research, development, and implementation. An important result of ROSE is the socio-economic value of reducing energy consumption by optimizing the road surfaces; as shown in research of the previous COOEE project, this is one of the few initiatives for reducing CO₂ emissions that has a negative socio-economic cost. Besides these values, if the ROSE research is successful, its results will be commercialized by the two Danish companies involved (NCC A/S and Greenwood Engineering), primarily from 2019 and onwards, and possibly also by the other partners involved.