Actions to protect road bridges and tunnels against terrorist attacks are rarely cost-effective, an EU-funded project has concluded.
Either the cost of protection must be very low or the piece of infrastructure must be very important for measures to be worthwhile on the grounds of attack resilience alone, according to the team working on the SeRoN (Security of Road Transport Networks) project. However, additional safety or traffic management benefits may tip the economic balance.
The three-year project, which is just ending, set out to study the regional and wider impacts of possible manmade attacks on the transport network. Seven partners were involved from six European countries, led by Germany’s PTV Group.
They developed a four-step methodology and toolset that: identifies and prioritises ‘infrastructure objects’ on the road network; evaluates the importance of the asset to the network; assesses the risk for potentially critical objects; and gauges the effectiveness of protective measures.
Results and conclusions from the project were presented this month at a summit in London on infrastructure risk and resilience, organised by team member Parsons Brinckerhoff and the IET.
SeRoN focused on bridges and tunnels because they act as bottlenecks and attacks have the potential to cause structural damage and substantial human casualties, as well as having economic, political and environmental effects. Dr-Ing Georg Mayer of PTV said that one problem was the huge number of infrastructure objects on a road corridor, forcing the team to modify their pre-selection method.
Selection criteria were based on traffic volume including HGV traffic, damage potential, reconstruction time and symbolic value. Assets identified as potentially critical were ranked according to their importance to the network by considering the consequences of non-availability, using traffic simulations. Then the most critical structures were assessed ‘as is’ and with possible protective measures. From this the effectiveness and cost-effectiveness of the measures can be established.
Mayer pointed out that detailed and comprehensive analysis of this type may not be affordable for most road operators. However, he said, “step 1 is easy, fast and reliable” and can be followed by further analysis for specific objects.
“One lesson learned,” Mayer continued, “is that from the engineering point of view there are hardly any cost-effective security measures. But it’s one view. If you take social and political views into account it may be different.”