This paper discusses results from real-life tests with intelligent road marking units (RMU), placed on the surface of a highway in northern Sweden, to monitor passing vehicles and road properties, as well as making the information available through a wireless sensor network. Wireless sensor networks are starting to gain interest in the area of cooperative safety and efficiency in transport as they can contribute to the reduction of accidents and emissions as well as enhanced driver experiences. Intelligent road markings are another key element for the creation of intelligent transport systems, complementing road side units, devices placed near a road equipped with high-performance computational platforms and long range communication capabilities. This paper shows that RMUs are feasible from the perspectives of low-power consumption, durability, and sensing performance.