Sometimes the temporary barriers have been installed despite existing bollards being in place. This is probably because the existing bollards are not strong enough to stop a determined driver in a heavy hostile vehicle.
In mid-September I was in Melbourne for the AITPM conference and noticed this example in the Bourke Street Mall. The temporary bollards are completely ineffective since a vehicle can quite easily access the mall using the tram tracks.
The Australian Government recently launched their Strategy for Protecting Crowded Places from Terrorism. As well as the strategy, the website includes some valuable tools that active transport and public space planners and engineers need to make themselves aware of when planning and designing crowded places. Crowded places could include outdoor dining areas, commercial hubs and CBDs, shopping centres, hotels, stadiums or special events. Relevant tools include:
- a self-assessment tool that provides an indication of the need for intervention to improve safety
- Hostile Vehicle Guidelines for Crowded Places
- Early intervention during planning provides the greatest opportunity for success and the cost of including security interventions increases as the project progresses through design to completed infrastructure
- Security should be proportionate to the threat and appropriate for the space
- Sculptures, bicycle parking, fountains and stairs can be effective security measures that add to the amenity of a crowded place. This blog post provides a nice discussion on some design ideas for beautiful bollards.
- To be effective, the maximum clearance between barriers cannot be wider than 1.2m
- The angle of the vehicle entry to the space can significantly impact on the cost of barriers
- Speed bumps and the like are ineffective in deterring or slowing down a hostile vehicle.
So, does this mean the death of the 'naked streets' concept? I don't believe so, it just makes it an inappropriate design solution in areas where there are crowds that gather.