Infrastructure

Along the A22, including a long section through the Alps,there are numerous road structures:

• 144 bridges and viaducts (31.2 km). The most significant road structure is the Colle Isarco viaducts (between Vipiteno and Brennero): it is 1,028 m long made up of 13 spans with a maximum height from the valley of 110 m. The Company has invested 12 million Euros to upgrade and modernize the structure.
• 30 unidirectional tunnels (12.6 km). Four of the 30 tunnels along the A22 have a length of over 500 meters. These are the tunnels in Brennero, Fortezza, Bolzano (Virgolo tunnel) and Trento (Piedicastello tunnel).
• 147 flyovers. Most of the flyovers along the A22 have been upgraded and are designed and constructed as an architectural enhancement to the specific areas, and to have thelowest impact possible on the environment.

The A22 is surfaced in special low-noise asphalt (DFAS). This combination of materials has been created to ensure greater safety and comfort on the motorway even during bad weather conditions. The only exceptions are tunnels, bridges and viaducts (extending over a total length of approximately 15 miles) which have been covered in an anti-skid surface for winter operations on the motorway.

MONITORING - The condition of the road surface plays a considerable role in relation to structural damage and the duration of its operational suitability. The use of technology to assess the fatigue properties of the road surface and therefore determine the integrity of the load-bearing structure is of vital importance. The evaluation of these critical parameters is used as a basis for the development of a method to determine the remaining useful life, to estimate the intervals for and scope of maintenance and replacement work, and finally to improve structural quality and the resulting long operational suitability of the road surface. The subsequent lower number of necessary road works will generate financial savings. These objectives will be met by employing an automated vehicle counting system to replace manual methods, which will measure the roughness of the road surface by travelling at motorway speeds along a linear section of the route. An automated measurement system is less resource intensive and provides a greater quantity of useful data regarding roughness while considerably reducing any problems with regard to safety and traffic monitoring which arise as a result of manual surveys and analyses. The system includes various tasks, from the specific analysis of the affected section of the route to large projects, including predictive analysis, estimation of road renovations, renovation quality assurance, etc.

• measurement of roughness for road surface management systems including any safety-relevant studies quality assurance
• measurements for new road surfaces for the certification of contractual specifications for the construction of the road surface with reference to the limit values for the roughness and separation of the concrete aggregates detailed
• measurements of the roughness and surface (wear, grooves, ...)
• evenness along and across the road surface
• faults with joints and cracks
• summary of the surveys of joints and cracks in any one section of the road surface
• documentation of the newly concreted surface
• faults in the road surface and examination of horizontal marks


In traffic engineering, the term “de-icing” refers to the act of preventing snow and ice adhering to the road surface. The snow clearing team scatter a de-icing agent on the asphalt prior to any expected heavy snowfall or if the surface reaches the freezing point of any liquid. If de-icing is necessary, a road weather information system is used which measures the temperature of the road surface and other meteorological and climatic conditions (wind, humidity, precipitation, etc.). However, such measurement stations may only be positioned at variable points a considerable distance from one another.

A better assessment can be obtained from an almost blanket coverage and the mapping of temperatures along the entire length of the route. Such imaging includes the collection of data about the temperature of the road surface in relation to its geographical location. This form of data presentation provides a thermal profile of a particular section of road based on a geographical determination. Road maintenance winter service staff are able to use this data to identify locations on the temperature map where temperatures lie below the critical limit thus indicating that these areas are more likely to develop a layer of ice and they are therefore able to decide whether they should apply chemical agents.

Based on the aforementioned facts, Autostrada del Brennero SPA has developed a mobile monitoring system for installation in highway maintenance vehicles (belonging to the road management service). This system is fitted with a data acquisition unit (non-contact IT sensors, GPS, GPRS, etc.) which captures, processes and transmits the temperature data in real time to a central server where a temperature map of the recorded road surface temperatures is created in a geographical information system (GIS).

Planning and trial of proprietary crash barriers for the safety of motorway users

The crash barriers along the A22 are constructed from Corten steel (S355J0WP as per UNI EN 10025-5), a stainless and resistant alloy (of carbon, manganese, silicon, phosphor, sulphur, nickel, chromium and copper) which oxidises when exposed to the elements. The patina, a thin, homogenous and resistant layer of rust, protects the steel underneath from corrosion and its colour blends well with the surrounding landscape. All “Brenner Motorway” crash barriers have been subject to crash tests and the majority are currently undergoing the Ministry of Infrastructure and Transport’s homologation process. The company is currently piloting its proprietary crash barriers in order to improve their performance.

Typologies

H2 - Designation: lateral delineation on raised stretches of the motorway with restricted height and potentially hazardous, intermittent obstructions. Criteria of the successful crash test:

• vehicle weight 900 kg – impact speed 100 km/h – impact angle 20°;
• bus weight 13,000 kg – impact speed 70 km/h – impact angle 20°.

H3 - Designation: lateral delineation on raised stretches of the motorway with great height and near potentially hazardous, intermittent obstructions or retaining walls. Criteria of the successful crash test:

• passenger vehicle weight 900 kg – impact speed 100 km/h – impact angle 20°;
• truck weight 16,000 kg – impact speed 80 km/h – impact angle 20°.

H4 - Designation: on curb of motorway flyovers or noise protection walls.  Criteria of the successful crash test:

• passenger vehicle weight 900 kg – impact speed 100 km/h – impact angle 20°;
• truck weight 38,000 kg – impact speed 65 km/h – impact angle 20°.

Central barrier H4 - Designation: central crash barriers between the two carriageways of the motorway. Criteria of the successful crash test:

• passenger vehicle weight 900 kg – impact speed 100 km/h – impact angle 20°;
• semi-trailer truck weight 38,000 kg – impact speed 65 km/h – impact angle 20°.

Integrated crash barrier - this is an integrated crash barrier/noise protection wall with the combined containment properties of an H4 crash barrier and noise absorption properties of a noise protection wall. This crash barrier is intended for use on the side of motorway bridges and flyovers. Criteria of the successful crash test:

• passenger vehicle weight 900 kg – impact speed 100 km/h – impact angle 20°;
• semi-trailer truck weight 38,000 kg – impact speed 65 km/h – impact angle 20°.

Containment section - Designation: Initial section of the crash barrier. Criteria of the successful crash test:

• passenger vehicle weight 1,100 kg – impact speed 110 km/h – impact angle 90°;
• passenger vehicle weight 1,100 kg – impact speed 110 km/h – impact angle 15°;
• passenger vehicle weight 900 kg – impact speed 100 km/h – impact angle 65°;
• passenger vehicle weight 900 kg – impact speed 100 km/h – slightly offset frontal impact.

Diversion route

The moveable system for the closing of thoroughfares is a crash barrier installed at regular intervals along the motorway network and which enables maintenance work and the diversion of traffic in the event of accidents, work or various requirements for the convenient and safe diversion of traffic onto the opposite carriageway.

Emergency call points have been installed along the hard shoulder at intervals of approximately one mile. Three different buttons enable contact to be established with medical services, breakdown services or the fire brigade.

Motorway users who break down on the motorway or experience other problems can use every emergency call point to make direct contact with the A22 User Service Centre (C.A.U.).

The fog system extends over approximately 65 miles along the most southerly section of the A22 (from Affi to Modena). It comprises LED guide lights and sensors to detect levels of fog. If visibility is restricted, the relevant section of the system is automatically activated.

The lights may burn continuously, flash or form a light trail in accordance with the speed limit stipulated. The system is connected with the User Service Centre (C.A.U.) and divided into 23 independent modules. Each section is fitted with its own light sensor and fog sensor (33 in total).