Last time you perched on a bench in a crowded inner-city place, you probably weren’t aware you were communing with the frontline against terrorism. Or that, when you admired a flower display in a public square, you were actually eyeing up several tonnes of “hostile vehicle mitigation” technology – the contemporary city’s equivalent of moats and ramparts, cloaked in granite and foliage.

Since terrorism has become one of the guiding forces in urban design, the incorporation of immense fortifications into everyday streets has spawned an entire industry of defensive architecture, complete with battalions of protective street furniture. It is a phenomenon that attempts to marry the desire of counter-terrorism agencies to erect enormous razor-wire-topped concrete walls around everything with the need for life to go on as usual. The spawn of this unhappy marriage is usually as clunky as you would expect. It marches around station squares and is strewn across corporate plazas all over the country, in the form of densely packed lines of chunky bollards, and granite benches on steroids.

The latest developments in this rising tide of urban paranoia are on display this week at the Counter Terror Expo in west London’s Olympia, a sprawling trade show that proudly claims to showcase “the key terror threat areas under one roof”. It is an enormous supermarket of neuroses, the rhetoric of threat and fear monetised into innumerable services and gadgets.

The BMW 7 Series High Security

Once you get through the extreme airport-style security, it feels like walking into Q’s lair, only reimagined in a suburban office park. Among the flimsy stands and carpeted booths, there are surveillance drones hanging from the ceiling, bomb-disposal robots with their disruptors cocked, and suitcases that open into portable forensics labs. Infra-red street scanners jostle for attention with machines that can x-ray entire aircraft, while mannequins in full combat suits square up against models apparently kitted out for chemical armageddon. One stand bristles with remote-controlled creatures brandishing alarming weaponry: “When danger is unknown, send the robots in first.”

As well as the gadgets, there are conferences and panel discussions tackling such questions as “Who is funding/fighting whom?” and debates about the baddies’ preferred social media network: “Twitter, Facebook, YouTube and WhatsApp: what each offers to terrorists.” But the crowds of burly bodyguards and the Middle Eastern ambassadors’ retinues seem more interested in trying out the features on the BMW 7 Series High Security, a 4.5-tonne executive saloon that appears to have all the features of a tank secreted behind its sleek bodywork. Its brochure lists all the different types of machine guns and hand-grenades it can withstand – along with a clean air system in case of gas attacks. So who’s the target audience for this hefty beast? “Anyone who has the feeling in their stomach that they might be at risk,” smiles BMW’s Wilfred Rohwedder. “Driving in this helps keep your stomach quiet.”

Suddenly, as I’m contemplating the thought of a £300,000 stomach-settler, a man in a wheelchair glides up, blood pouring from a gunshot wound to the forehead, hotly pursued by a one-armed man blistered with chemical burns. In the midst of this disturbing gauntlet of panic rooms and cyber threats, it’s easy to believe that a tactical unmanned system might have gone awol and started firing at its makers.

Facebook Twitter Pinterest A simulated limb amputation by Magnum Services

The gravely wounded chaps are in fact promoting their casualty simulation company, Magnum Services, specialists in gory reconstructions of terrorist attacks and other disasters. Their team of actors and makeup artists can supply everything from lacerations and scarring to amputations, catastrophic haemorrhaging and eviscerations. “Below-knee amputations are the most common request,” says Ruben Carril cheerfully. Carill is a real-life amputee whose company provides services to the Ministry of Defence and NHS. “It’s about desensitising people to the reality of these traumatic injuries, so they can get on and do their job effectively when it actually happens.”

Another experience company peddling its ghoulish wares is Caliber-3, an Israeli outfit that describes itself as a “leading counter-terror and security academy”, staffed by special forces soldiers from the Israeli Defence Forces. For a hefty fee, the company offers tailored training programmes, from urban combat and VIP protection to tourist courses including Bar Mitzvah shooting days and the fun-for-all-the-family IDF Shooting Adventure, “which over 6,000 visitors per year enjoy”.

But alongside these fringe pursuits aimed at fear fanatics are the security systems and surveillance technologies that have already infiltrated our daily lives. Tech giant NEC is showing off its NeoFace facial recognition system for CCTV footage, whose fiendishly clever algorithms can match your face, in real time, to an existing photo database in a split second, no matter how grainy the footage. It might sound like crime-fighting of the future, but NEC’s Chris de Silva says it is already used in 40 countries worldwide. Leicestershire police became the first UK force to adopt the technology last year, saying it could save tens of thousands of hours of manual photo cross-referencing. But critics fear it cranks up the invasion of personal privacy to a worrying level.

And then there are the fences. Lots of enormous fences, available with various “toppings”, from electrified wires to sensor detection systems and good old lacerating razor wire. They’re marshalled together with the defensive street furniture, and all these bulky chunks of infrastructure look a bit forlorn compared to the robots and invisible cyber-threat fighters being showcased elsewhere.

“We’re increasingly being asked to turn our attention to threats other than lorries carrying bombs,” says Mike Webb of the Perimeter Security Suppliers Association, the trade body for the bollard and fence-makers. “Cyber is the next big thing, along with aerial and electrical attacks.” If you can hack into an electrical gate-operating mechanism, it’s really not much use.

Facebook Twitter Pinterest A woman eats her lunch on a counter-terror block in London

The perimeter protection industry, he says, shot up overnight as a result of the Glasgow airport terrorist attack in 2007, when a jeep loaded with propane canisters drove straight into the terminal. “It was set up in a matter of weeks,” he says, “so we needed to set standards very quickly.”

This speed, plus the perceived severity of the threat, has left us with a legacy of vastly over-specified chunks of concrete and steel installed at every possible opportunity, in the event that a 7.5 tonne lorry might drive head-on at 40mph – the gold standard of terror that such defences must withstand. The specific nature of these defences is governed by PAS 68, the British Standards specification, and set by lengthy crash-testing, which decrees that bollards must be spaced no further than 1.2m apart. The mega concrete blocks, meanwhile – now often disguised as benches and planters – are a legacy of temporary road blocks used during the Troubles in Northern Ireland. As often happens, standards set in times of crisis then filter into the mainstream without much questioning – until our cities are choked with bollards and blocks.

“The terror threat is now much more sophisticated than ever before,” adds Webb, “which makes you wonder, are we just going to stick with these great big fences forever?”