Video surveillance systems and traffic monitoring
It is vitally important that the surveillance staff in the control centre are actually able to see what is happening at the trouble spots along the route and in particular in areas where there is a greater likelihood of critical situations such as delays, accidents and traffic jams occurring. Staff are able to use such images to instigate any safety or control measures required in sufficient time to guarantee the highest level of safety to motorway users and therefore as little discomfort as possible.
In this context, the introduction of automated mechanisms is seen as indispensible in order to prevent technological or control problems with the many installed cameras in relation to the traditional methods of surveillance in the control centre.
One of the basic innovations of the AID systems (Automatic Incident Detection) is the capture of data and automation of the analysis process by which the captured images are processed by digital means and algorithms. When problems arise (accidents, traffic jams, delays, a motorist driving against the traffic, etc.) the image processing algorithms generate an alarm which is then forwarded to a control point at the headquarters. These systems also record the incident including a short period beforehand in order to be able to reconstruct the dynamics of the incident which has occurred
Traffic data collection systems
It is very useful for the control centre to know exactly how many vehicles are on each of the various motorway sections at any one point in time in order to be able to evaluate and predict traffic conditions and as a result implement measures to regulate the traffic at critical points, such as entrances to toll booths or along the route itself, and to provide motorway users with information about delays, traffic jams, etc.
In order to be able to fulfil this function, all vehicles joining, using and leaving the motorway network must therefore be counted. The difference between the number of vehicles joining and leaving gives the exact number of vehicles on the motorway in real time. The process of calculating this number also shows whether the level of traffic in the individual sections is increasing or decreasing; this data may also be used in conjunction with historical data to create precise prognoses for anticipated traffic flows in the core holiday season.
Non-contact sensors have been installed in the gantries along the route of the Brenner Motorway and induction coils laid under the road surface. Both are able to supply all essential traffic data (counts, speed, vehicle classification, etc.).
TUNNEL SAFETY - Water Mist System
A fire protection system with automatic fire extinguishment using water mist (water atomised at high pressure) has been installed as part of the regular maintenance work for the reconstruction of the Virgl Tunnel (BZ). The system developed out of a European research project (Uptun) in which the motorway company has been participating since 2002.
These high pressure atomisation systems differ from traditional sprinkler systems in terms of their significantly higher pressure (80-140 bar in comparison to the usual 10-15 bar of a traditional system) and the much lower water flow rate. In terms of construction, the most important differentiation factors relate to the use of pumps with a high supply pressure and the use of special nozzles. The combination of these elements means the system is able to produce micro droplets of water of a substantially smaller size: 10 micron instead of 1000 micron.
The intrinsic surface of the generated droplets is therefore approx. 200 m2/litre in contrast to the conventional 2 m2/litre of traditional systems. Since extinguishing power is proportional to the intrinsic surface, it is obvious that it will be significantly greater as a result of the high pressure atomisation
MONITORING - Integrity of load-bearing structures
The monitoring of load-bearing structures is one of the most modern and effective techniques used to inspect the behaviour of load-bearing structures and for the accurate evaluation of all functional parameters characterising the load-bearing structure. The term monitoring system is taken to mean the combination of all devices used to capture, handle and transmit as required the data for the examination of a load-bearing structure during its useful life.
The performance of a load-bearing structure decreases year on year throughout its lifetime and the residual degree of safety no longer corresponds to that in the construction plan. To guarantee the safety of the load-bearing structure and its users, the integrity of the load-bearing structure must be guaranteed in terms of its safety in relation to the limit states of the load-bearing capacity and fitness for purpose. The development of suitable strategies for the renovation and extension of its useful life requires devising and resolving aspects such as how to monitor the life cycle, the lowest degree of safety and the maintenance strategies from the point of view of reliability over the years and the administration costs.
The main problem consists of identifying the development of any potential faults and advanced degree of wear in good time, and preventing such phenomenon, effectively assessing their causes and severity, and enabling a suitable plan of action. Any process organised in this manner enables the effective prioritisation of planning and above all allows the effectiveness of any actions implemented to be inspected in due time. An optimum strategy will meet the criteria of the minimum life cycle. The aim is to minimise the expected total cost by always complying with the conditions for the safety and reliability of the load-bearing structure.
The motorway bridge at Gossensass, for example, is fitted with sensors to allow the 24 hour monitoring of electrochemical and mechanical parameters (corrosion potential, concentration of chloride ions, temperature and moisture, deformation and flexural behaviour of the load-bearing structure, etc.). From time to time measurement campaigns will also be carried out to examine the dynamic properties of the load-bearing structure.