This is the Reflexstone by Kijlstra Bestrating from Veendam, a concrete paving brick where the topmost layer has partly been equipped with Luxovit, a reflective road metal. As a result proportionally less light is required for an equal degree of luminance.
The bricks are available in a number of colours. The luminance gain differs by colour and also depends on the amount of luxovit used. The yellow Reflexstone, for instance, realises savings of approximately 7 % compared to the standard yellow concrete paving brick. For the red variety this increases to 35%. The material may also be used in other concrete products, concrete kerbs along bike paths may for instance also be made reflective.
In Groningen in particular the reflective pavements is being used in a number of locations. Besides near the bicycle flat near the train station provincial authorities have also used the concrete kerbs on a road near the town of Pieterzijl in order to improve a bicycle crossing. And Groningen Seaports is constructing a bike path with the red reflective stone as part of the Revitalisering Oosterhorn project.