RED-WINE: an advanced Wireless Sensor Network for real time road infrastructure monitoring

Intelligent Transportation Systems (ITS) aim to improve road transport safety and efficiency, to manage road networks in the interest of the society and to provide real time responses to events. Monitoring equipments for road and traffic conditions (inductive coils, remote cameras, weather stations, acoustic systems, ...) are on the market, but a fully integrated solution is not yet available: every system relies on public networks (usually cellular networks) or custom communication systems to send data to Traffic Control Centres. Recently, Wireless Sensor Networks (WSN), i.e. networks composed of many low-cost sensors, laid along roads and connected through radio links, have been proposed as an alternative to current high-cost localized traffic measurement systems. However, available WSN communication protocols are not suited for ITS systems, due to their unpredictable latency and to the energy consumption of nodes. This paper presents RED-WINE (Roadside Event Detection - WIreless NEtwork), an innovative system composed of multi-sensor nodes, or GRAPEs, installed on the roadside. RED-WINE is a low power, low cost, easy to maintain and open solution to automatically generate safety warnings at ‘black spots’. The system supports configurations ranging from isolated (to monitor a spot) to fully distributed (to monitor a road) always using the same sensor technology. The isolated solution is already a commercial product, with nodes installed at critical roadside points in order to detect local events, and is described at the beginning of this paper. The know-how acquired from it lead to the implementation of the distributed system, where a large number of nodes, communicating using a new protocol leveraging on their linear topology, can cover stretches of road up to 5 km in length. Its implementation and testing was done in the EU co-funded projects Safespot, SAVEME and COSMO.