On the southern end of London Bridge, ugly black barriers make the narrow pathway passable only to the thousands of commuters who hurry across the River Thames every day to the city’s financial district. Early morning cigarettes stubbed out in a handily-shaped hole on top of a barrier have been turned into a soggy mess by rain.
The installation - prompted by a terrorist attack in June that left five dead and nearly 50 injured when a van mowed down victims on the bridge - is complemented by roadside concrete blocks, streaked with red paint after London bus drivers were caught out by the narrowed road.
For a bridge that doubles as one of the city’s greatest sightseeing platforms – with views to Tower Bridge upriver to the east - it is not a great look.
Yet the security measures highlight issues that authorities around the world are facing as terrorists increasingly target public areas rather than highly-protected national infrastructure.
In most countries, anti-terrorism measures have been watered down or dropped entirely from building projects because of costs, resulting in the use of concrete blocks by authorities under pressure to react to major events, said experts.
The warning signs date back to at least 2010 when Al Qaeda’s Inspire magazine published an article titled the “Ultimate Mowing Machine” that advocated using four-wheel-drive vehicles against the “enemies of Allah”.
The exhortation has been heeded to deadly effect since, with a string of attacks using stolen lorries, hired vans and cars. The latest, on Las Ramblas in Barcelona last week and in the Spanish seafront resort of Cambrils several hours later, left a total of 15 dead.
Eighty-four people were killed in the French city of Nice when a militant Islamist used a 20-tonne truck to run down crowds gathered to watch Bastille Day fireworks in July last year.
In December, an ISIL supporter ploughed into a bustling Christmas market in Berlin, killing 12. The London Bridge attack was the second time in three months that a vehicle was deliberately driven into pedestrians crossing a bridge in the British capital.
Such attacks have shifted the focus of security professionals from car bombs to so-called vehicles as a weapon, dubbed VAWs, driven directly into crowds.
“That’s what has got a lot of people scratching their heads,” said Gavin Hepburn, sales director at ATG Access, a global supplier of protective equipment. “It’s quite hard to buy explosives here and in other countries – but it’s not too hard to hire a van.”
Governments have been forced to work out how to protect citizens while keeping high-profile public areas attractive places to live and work.
The use of concrete blocks shows that cities have failed to incorporate effective anti-terrorist features, and are more for public reassurance, according to the security industry.
“In the aftermath of attacks ... obtrusive security features – notably temporary concrete or steel blocks – are commonly ‘thrown’ around key sites to stop vehicle attacks,” wrote Jon Coaffee, professor of Urban Geography at the University of Warwick, in an article for The Conversation. “They are not necessarily aesthetically pleasing.”
At Bicester Village, a shopping outlet close to Oxford, one-tonne multi-coloured blocks have appeared on walkways into the centre, accompanied by a four metal-girder art installations that spell out the word “Love”.
The company who supplied the blocks says they can be used for construction, fencing, scaffolding and supporting gantries – but does not mention security. The shopping centre, a popular stop for coaches of Chinese tourists, did not respond to requests for comment, but experts dismissed the likely effectiveness of such measures.
“On their own, they’re not effective, they can be negotiated fairly easily by a normal size car let alone a truck at speed,” said Mr Hepburn. “It’s very much a knee-jerk reaction.”
The installation of concrete blocks in Melbourne in June sparked a “Bollart” protest driven by social media which saw them dressed in fabric and painted with messages against the building of Australia’s largest coal mine. “Nothing more offensive than a nude bollard,” one person commented on Twitter.
French officials said in February that it would build a 2.5-metre bulletproof glass wall around the Eiffel Tower to provide protection from terrorist attacks.
In Cologne, large stone blocks will form a barrier in front of the city's cathedral after it emerged that the Barcelona plotters had planned to target Antoni Gaudi’s unfinished masterpiece, the Sagrada Familia basilica.
“We don't want to wall up the city,” Andreas Geisel, Berlin's interior minister, told Bild. “That would achieve the opposite of what we want: to send out an image of calm and relaxedness.”
The best protective bollards and barriers can stop a 30 tonne truck travelling at about 80 kilometres per hour, but no country currently has mandatory design rules to deal with such eventualities. Singapore will become the first to introduce such controls later this year, according to Paul Jeffrey, the managing director of UK-based Avon Barrier.
Projects including the new Adnoc headquarters in Abu Dhabi and Doha international airport are relatively rare global examples where anti-terror measures have been built into the designs, say experts.
There are many more examples of poor practice, according to the industry. One project to introduce effective security at an unnamed UK sporting venue has been scuppered by planning rules, according to Mr Jeffrey. He said problems will not be resolved before the venue hosts a major event there.
The UK government issued a 174-page document days after the London Bridge attack titled “crowded places guidance”, which highlighted how public seating and solid planters could prevent the threat. Just several hundred metres from the bridge, a modern and popular plaza with office workers from blue chip companies and close to London’s main government building is unobtrusively protected from vehicles by trees in large planters, water features and large stone public art installations.
“We can avoid the use of ugly concrete blocks except in emergencies; wrought iron, cast iron, even wood is enough,” claimed former MP Matthew Parris in a Times column last week.