Egnatia Motorway in Greece is one of the largest road construction projects in Europe and creates a vitally important link to the rest of Europe in one direction and Asia in the other. It wanted to develop a wireless traffic surveillance project along the nine kilometers of the motorway that runs from the Metsovo interchange to the Peristeri interchange. Despite being only nine kilometers in length, this route has the most difficult and varied terrain on the motorway, hence the need for surveillance cameras.
A comprehensive study was undertaken to determine the best approach to the project and revealed a number of unique factors for consideration. The complexity of the terrain meant that a more traditional point to multipoint topology would be impossible. Instead, the wireless solution provider who came up with the study recommended that a serial (cascading) scheme with multiple point to point junctions. IP-based surveillance cameras would deliver the necessary functionality for the project including pan, tilt zoom functionality, high definition images and warnings of irregular ˉeventsˇ such as a traffic accident. The network topology meant that load would gradually increase because of the cameras, peaking at the final point. There were 13 junctions that required installation along the length of the highway and six of them were not visible because of tunnels and bends in the Egnatia Motorway. The cameras needed to be spaced relatively far apart approximately one kilometer between each one. Another key requirement was that the cameras and the wireless equipment needed to stand up to the adverse weather conditions which prevail in the area, such as continuous rainfall for most of the year, very low temperatures, strong winds and a high snowfall during the winter. It was also recommended that the system output should not vary noticeably when large vehicles pass, especially between tunnels.
In order to satisfy the complex mix of requirements dictated by the survey, the projectˇs contractor recommended a combination of Axis 213 PTZ network cameras and Proximˇs Tsunami MP.11 5054-R. The Axis network cameras met a number of requirements dictated by the environmental conditions including pan, tilt, zoom functionality, the ability to operate under all light conditions and a vandal-resistant and outdoor-proof housing. Crucially, the cameras can send alerts about unusual traffic events to motorway staff. To ensure high-quality video transmissions, the project contractor insisted that the cameras initially support the M-JPEG video format and later MPEG-4. Since the Axis Camera Station supports both high quality recordings in M-JPEG and MPEG-4 format, this requirement was easily met. The built-in 26x optical zoom, auto focus lens along with 12x digital zoom ensured that the camera could be placed one kilometer apart as required. The combined solution delivered excellent performance and met Egnatia Motorwayˇs complex mix of requirements.
Following the successful deployment of the project, the regionˇs control center now has full command over the network cameras and the combination of high bandwidth and low latency of wireless network ensures that high quality images are constantly available to motorway staff. Staff members are also alerted to unusual traffic events so they can respond accordingly. The system is completely secure and can be managed remotely.