In the context of road infrastructure, in particular road tunnels, security is understood as the preparedness, prevention and preservation of a road infrastructure against exceptional man-made hazards. This definition of security is complementary to that of safety, which is defined as the protection of road infrastructure against unintentional events such as accidents and is covered by relevant standards. Thus, the key distinction between security and safety is that:
Security-relevant hazards which may affect road tunnel infrastructure, operations and users are e.g. terrorism, cyber-crime, theft or hoaxes.
In order to analyse the security level of an infrastructure and to decide about the implementation of protective measures, a security assessment should be conducted. The security assessment consists of a hazard and scenario analysis, a determination of the vulnerability of the asset and its important components (object level) and finally the consideration of the tunnel’s criticality (network level), meaning its importance for the road network as well as any interdependencies with other transport infrastructure and other sectors. In order to prioritize tunnels to be strengthened by protective measures, the criticality of the asset is the key criterion. It is recommended to rank elements of infrastructure according to their criticality before deciding on budget allocation for protective measures.
Regarding protective measures which could be implemented in order to strengthen security, there is generally a large overlap with safety measures (the boundaries between safety and security are often not clear). This overlap can be used to strengthen both safety and security and could help to get the necessary funding for protective measures. The same is valid for already implemented measures in existing road tunnels: many existing structural and operational safety installations could be used to prevent or mitigate both safety and security related events (e.g. cameras (CCTV) or incident detection systems (IDS)). Generally it is recommended to include security principles right from the conceptual and preliminary design phases for a new tunnel (“Security by design”). Retrofitting an existing infrastructure with security measures is often much more expensive. When considering protective measures for existing structures, low budget security solutions in particular or measures with synergies with safety should be implemented. Additionally so-called “soft measures” should be taken into account (e.g. organizational measures, staff training, etc.).
For more detailed information refer to the technical report 2015 R01 “Security of road infrastructure”. The report contains also useful references and links to existing international literature as well as procedures and tools for security assessment. Some useful examples for protective measures are also mentioned in this report. Other PIARC outputs related to security that could be relevant are for example: