Pushing back the boundaries

Access control for our front and internal doors has been with us for many years, and will certainly be around for many more years to come. Indeed, the technology has advanced considerably during the past decade or so, spanning the entire range from very simple single door systems right through to fully-integrated networked systems running over IP, communicating with multiple sites in different areas and even in different countries.

Due to the pressures of increased security and the ongoing requirement for more advanced management control, end users' access control systems are steadily moving beyond the front door of their company's building(s) and out into the car parks, industrial estates and transport networks that lie beyond.

From a security standpoint, the 'security perimeter' – which, traditionally at least, stopped at the aforementioned front door – is constantly being forced further out, away from the building(s) and the occupants within. In sensitive high security areas, for example, the perimeter is being extended beyond the blast radius of a lorry or car bomb. This presents a whole new set of access control problems that only specialists in the field should be entrusted with solving.

While this secure perimeter might be fairly easily extended on an industrial estate or out-of-town business park, imagine the problems faced when trying to extend that perimeter for a town centre or City office complex where hundreds of people arrive and pass through on a daily basis. It's fair to say that nothing less than the most advanced and reliable access control system would be required if total chaos were to be avoided.

Not only are security managers responsible for controlling the movement of people, they're now also taking charge of controlling the movement of any vehicles on to and away from a site. The range of available control options has grown considerably in recent times, although the automatic vehicle barrier is still the most popular for the majority of general applications due to the cost-effectiveness of installation and improving reliability.

For more secure applications, and where aesthetics are important, automatic rising bollards or automatic gates might be considered for specification. When high security is more important than access control, road blockers and rising kerbs providing ram protection would be deployed. All of these devices engender controlled access and exit for vehicles, but they also serve to slow down traffic flows (which may or not be an advantage to the security team depending upon the application in question).

Where smooth, fast traffic flow is very definitely a requirement, there are a range of Automatic Vehicle Identification (AVI) products available which can speed the passage of vehicles through a given control point. Obviously, these products are only fitted to authorised, known vehicles, with visitors still being required to stop at control points.

Vehicle tagging: a flexible solution?
In its many and varied forms, vehicle tagging arguably provides the most reliable and flexible solutions for high performance AVI, the latest Automatic Number Plate Recognition (ANPR) systems running close behind with new advances in sophistication and performance.

Vehicle tagging is a radio frequency-based technology, and with the long range reading distances now on offer (ie up to several metres) interference can be a problem. It’s best to specify a microwave-based system such that any interference is almost total

In an ideal world, vehicle tagging would be used with ANPR in a complementary relationship, providing total coverage for authorised vehicles and the identification of unknown cars and lorries.

Vehicle tagging – whereby the vehicle concerned is given a uniquely numbered tag, usually positioned in the windscreen – is akin to affording each vehicle its own proximity card. The tag will be read by a long range reader (or, in the case of an under-vehicle tag, by a road loop fitted into the road surface).

The access control procedure is then exactly the same as it is for buildings, whereby the tag number is fed through to the control system which makes the decision as to whether or not the barrier/gate will be opened.

There are many different AVI vehicle tagging systems on the market today, and due consideration must be given in the selection process as to the most appropriate system for the application at hand. Vehicle tagging is a radio frequency-based technology, and with the long range reading distances now on offer (ie up to several metres) interference can be a problem. It's best to specify a microwave-based system such that any interference is almost totally eliminated.

When a tag is fixed to the underside of a vehicle, long range reading isn't usually a problem since the tag is normally within a metre or so of the inductive loop in the road surface. This type of tagging system is normally restricted to commercial vehicles, ambulances, buses/coaches and logistics fleet vehicles as the tags require permanent fixing to vehicle chassis, and may also draw power from the overall vehicle power supply.

ANPR on the advance
ANPR systems have probably advanced more than any other type of vehicle recognition system these past few years. There are now many different solutions on the market, all quoting differing levels of performance and reliability. There's one useful tip that all security managers looking to specify ANPR systems should bear in mind, though…

If an ANPR or AVI salesman starts quoting you 100% performance levels, your best course of action would be to show him or her the door immediately!

ANPR systems comprise several components, the absolutely critical parts being the camera and system software. You can have the best ANPR software in the world, but if the image from the camera isn't clear, the software will not stand a chance of interpreting the data accurately. Similarly, even the very best camera image will be completely useless if the software isn't up to the job. Remember, too, that ANPR systems have to deal with many different types of number plate, dirty plates, foreign plates and personalised plates – and do so in all of the worst kinds of environmental conditions possible (including the brightest days and the darkest of nights).

ANPR systems comprise several components, the absolutely critical parts being the camera and system software. You can have the best ANPR software in the world, but if the image from the camera isn’t clear, the software will not stand a chance of interpret

Traditionally, ANPR has been used for 'trend analysis' and traffic congestion applications. More recently, though, advances in performance levels and read reliability have seen ANPR deployed in many more types of access control application. Indeed, when installed and used in the correct manner and application, performance figures of over 90% can be achieved with the latest systems.

Pushing back the boundaries
Some recent examples of installations where vehicle access control has been used to successfully push the security perimeter outwards illustrate the trends well.

For instance, a 'rat run'-style problem has been affecting a prestigious office development and business complex on the outskirts of Edinburgh (client confidentiality precludes use of the real name here). At peak times, the business park has suffered from near gridlock, with unauthorised drivers clogging up the roads in trying to take a short cut to the nearby motorway.

The solution was to install automatic barriers at the main entrances and provide the 2,500 office workers on site with vehicle tags. This solved the congestion problem immediately, while still allowing visitors to gain entry using either a typical keypad-based system or an intercom linked to a central Control Room. Spread over several kilometres, the network of long range readers, keypads and intercoms is controlled by a single PC.

A growing number of town and city centre security managers are adopting AVI techniques to protect and secure newly pedestrianised areas prone to unauthorised parking and congestion. Physical vehicle control may be installed relatively easily at either end of the pedestrianised area, with buses and other city council vehicles fitted with tags for instant automatic access and egress.

Meantime, one of the largest shipping ports in the UK now uses under-body vehicle tags on all of its container shunting trucks to control access around the internal port roadways. Vehicle barriers are fitted at all the strategic points, which keeps the roadways clear for the shunting trucks and maintains a safe distance for vehicles belonging to members of the general public. The whole system is networked to the central Control Room.

Cutting back on drive-offs
A major logistics chain is currently trialling an advanced AVI system for both exit control and access control across its major UK depots. Given the number of drivers, trucks and trailers involved at these depots, the new system not only protects the site from drive-offs but can also securely check the combination of driver, truck and trailer before they're allowed to leave site. With the possibility of linking the entire UK distribution network back to central headquarters, it would be possible to ascertain the depot location of any trailer in the fleet.

Vehicle tagging and ANPR allow security managers to provide accurate access control for all vehicles, at the same time helping to push the security perimeter further and further out. No bad thing in an age where the threat of terrorism is now ever-present.