# Advancing Road Infrastructure Safety with the Remotely Piloted Safety Cone
## 4 Discussion
From its structural and electronic design to its navigation and control logic, the system has been conceived to comply with all current European regulations regarding active signalling (UNECE R65 [23]), structural and mechanical resistance (UNE-EN 13422:2019 [22]), luminous visibility (UNE-EN 12352:2006 [25]), and electrical safety (UNE-EN 12899-3:2008 [24]). The RPSC incorporates a structured operational lifecycle composed of the INITIALISING, WAITING RTK, FOLLOWING, ALERTING, and SHUTDOWN states, managed through a modular architecture based on ROS2. This cycle allows the system to autonomously control its transition between states based on the status of GNSS positioning, the detection of external events, the reception of remote commands, or the occurrence of internal failures. In terms of navigation, the system integrates a sensor fusion scheme based on GNSS with RTK, encoder odometry, and inertial estimation, enabling the maintenance of high trajectory precision. In tests performed under optimal configuration, the system achieved an average positioning error of 0.12 m and an average route deviation of less than 0.20 m. These metrics confirm the system's feasibility for precise operations in real road areas, where exact cone placement is required to define safety perimeters and work zones. To contextualize the performance of the RPSC, it is essential to compare it with the time required for manual deployment of traffic cones in real-world work zone scenarios. Field studies and government reports indicate manual cone placement is labour-intensive and time-consuming. According to Highways England, the manual assembly of a 1 km lane closure by two operators typically takes about 15 min, which equates to an average cone placement rate of approximately one cone every 7 to 8 s [27]. Moreover, this task generally involves transporting multiple cones simultaneously, which increases physical fatigue and reduces the operator's average walking speed from approximately 1.4 m/s unloaded to as low as 0.78-0.82 m/s when carrying loads exceeding 10 kg [28; 29]. This, in turn, increases the total time required to delimit large-scale work areas. In contrast, assuming a standard cone spacing of approximately 10 m and a maximum speed of 12 km/h (\(\approx\)3.33 m/s) for the RPSC--achieved using 248 RPM motors and 135 mm diameter wheels--the estimated time to position each cone would be roughly 3 s, which is significantly lower than that of manual operations. This direct comparison highlights the operational superiority of the automated system, both in reducing the time required for road zone segmentation and in minimizing worker exposure to vehicular traffic. This design allows for safe deployment in work zones and lays the groundwork for future research in multi-agent coordination, integration with intelligent construction management systems, and predictive risk analysis in road maintenance areas. The proposed hardware and software architecture has been designed to support scalable multi-agent operations to address the control and coordination of multiple RPSC units. ROS2 middleware enables each RPSC to operate as an independent node within a distributed network, using unique namespaces and individual identifiers to ensure isolated management of commands and telemetry for each unit. Remote control and supervision are achieved via a central ground control station (GCS), which communicates with all RPSC units through a ROS2-based interface. The GCS can issue individualized and group commands using ROS2 topics and services that manage structured messages for navigation, alarm activation, or operational state changes. Each RPSC exposes these topics within its namespace, allowing it to receive and execute commands synchronously or independently, depending on the operational requirements. Communication between the GCS and the RPSCs is handled securely and efficiently over Wi-Fi networks, with the ROS2 DDS backend ensuring automatic discovery, low latency, and the integrity of critical messages.