Operation and maintenance are clearly an important issue for a PIARC Committee that a few years ago changed its name to the Committee for "Road Tunnel Operations".
Operation and maintenance activities can be considered as divided into three main streams of activity:
Efficient operations and a cooperative environment among different stakeholders in charge of tunnel and emergency management clearly underpin the safety and comfort of users and operators both in normal operations and in the event of an accident.
Considering the European context, the Directive 2004/54/CE on "Minimum safety requirements for tunnels in the trans-European road network" clearly states that safety is not only related to structures and equipment. In fact the directive identifies a special role for activities related to Operation and Maintenance.
In order to successfully and efficiently operate and manage a road tunnel, operational tasks and the responsible body for carrying them out, need to be established in order to ensure that all actions required are handled in a consistent and safe way (Section Operational tasks). The level of safety provided for tunnel users is highly dependent upon the specific characteristics of the tunnel, but it also depends strongly on operational procedures and the people who are in charge of the tunnel.
The people in charge do not necessarily need to belong to the same organisation: players and roles can be quite different. For example, the traffic police are normally in charge of traffic, but the task is sometimes carried out by a road administration, and in some cases several tasks are entrusted to a private company/operator. Moreover, the same task (for example: traffic management) can be performed by many different bodies (operating staff, police, subcontractor), so the relative roles and responsibilities have to be specified as well as recommendations to improve the behaviour of people involved in tunnel operation and their level of cooperation (Section Players in tunnel operation and their co-operation).
In each case the organisation of the operation and coordination with all the different bodies must be deﬁned, by written procedures and protocols that are simple and straightforward, so that they are clearly understood by all parties and are robust under pressure in emergency situations.
The organisation of the operation can be quite different from one tunnel to another; consequently it is difficult to define an overall common framework. However, it is convenient to assess for each tunnel or group of tunnels the best-fit organisation to be adopted both during the standard operation and in the event of an emergency situation (Section Organisation of operations).
Moreover it is essential to establish standard operating procedures as well as minimum operating conditions and emergency plans. This is in fact a key step in planning the operational response to possible tunnel emergencies for which there need to be appropriate specific responses to various types of incidents (Section Operating instructions, minimum operating conditions, emergency plans).
The management and day to day operation, as well as the maintenance of a tunnel, involve high operational costs and funding requirements. In fact tunnels are among the most costly parts of a road network to be operated (in terms of energy requirements, staffing and monitoring). The definition and optimisation of the different cost elements in a tunnel and appropriate recommendations to reduce them have been analysed by the PIARC tunnel committee. The efficient use of energy and the progressive reduction of energy consumption should be considered, with a view to delivering a sustainable operation of the road network (Section Operational costs).
The final objective is clearly to guarantee an appropriate level of service and quality to the users. The achievement of the objective obviously depends on the nature and overall performance of the facilities and equipment. The performance of the equipment often depends on how this equipment is operated by the tunnel staff in terms of timeliness and appropriateness. Therefore the staff called to perform operational tasks must be well selected when recruited, well trained before starting their tasks and continually throughout their careers (Section Staff recruiting, training and exercise).
The safety level or the traffic capacity in a tunnel are influenced by changes characterising the road network and the evolution of the traffic itself. The tunnel operator may occasionally need to make minor or major changes to the system or to the management criteria to cope with these changes. It is therefore necessary to monitor changes and accidents using information and feedback, to continuously and systematically improve tunnel operations.
The operator needs to receive feedback from the experience of operation to be used to make choices for the improvements (Section Feedback from operation and incidents).
Structural elements and the technical equipment need regular maintenance whose goal is to ensure safe driving conditions for the public by keeping the tunnel at its designed safety standard (Section Maintenance of equipment). General recommendations for maintenance in tunnels are defined as well as the speciﬁc features and their facilities.
When the tunnel equipment no longer satisfies the needs of the operator, the requirements of legislation or when the nature or the level of traffic changes, it may be necessary to upgrade or refurbish the tunnel. For the refurbishment of an existing tunnel, recommendations mainly concerning measures to facilitate the management of trafﬁc network, equipment reliability and durability and whole life costing are defined (Section Operation during maintenance and refurbishment works).
The present chapter 4 essentially concerns tunnels of medium to long lengths, with medium or heavy traffic volume, located in places where prompt external emergency interventions are possible.These tunnels are operated with a specific organisation, dedicated to one tunnel or a group of tunnels, which are part of the same road network.
Section Short tunnels and/or very low trafficked tunnels presents the specific conditions concerning short tunnels, or very low trafficked tunnels, or scattered tunnels situated in areas with low population densities.
This Chapter was written by Working Group 1 of the C4 committee (2008-2011) in which: