Although the fixed nature of roads would suggest fixed connections would be the most suitable link for the networks of sensors, toll equipment and cameras, wireless technologies are being used more and more often.
Wireless technologies from low power radio up into the higher reaches of cellular performance are being deployed because they are easy to roll-out and they are reliable. Nobody wants to dig up a motorway to install or maintain hard-wired networks.
Local authorities and road operators across the world have recognised the value wireless technologies can provide in supporting networks of this type. IBM, for example, has partnered with Birmingham City Council in the UK to analyse big data to help it understand parking patterns and thereby manage congestion more effectively.
Others such as Georgia Department of Transportation in the USA have deployed systems to improve the efficiency of traffic flow and limit pollution (see box below).
‘Wireless sensor networks are a core aspect of future smart roads,’ says Dr Kevin Curran, an IEEE technical expert. ‘Monitoring bridges is one of the more successful applications of Smart Roads to date. In Greece, the 3km Charilaos Trikoupis Bridge has sensors and shortly after opening they detected abnormal vibrations in the cables, leading to engineers installing additional weight to dampen the cables.
‘Wireless sensor networks combined with cameras are becoming a common instrument in detecting traffic flows, speed, and the continued occupation of the road,’ adds Curran.
‘Sometimes they are combined with other sensors such as magnetometer or power sensors, for traffic detection. The advantages of wireless sensor networks are that they can monitor and evaluate roads automatically and continuously, with little human effort and work 24/7 even with poor weather conditions, when there is fog or presence of dust in the air. They are also low power and quite cheap.’
However, for more critical applications, cost isn’t the key consideration. ‘Deployment of wireless technologies by road operators is not about finding a cheaper alternative to fixed networks,’ says Kamal Mokrani, the vice president of InfiNet Wireless.
‘The key driver is reliability, they want something that works 100% of the time – a five second delay could be a big deal if you’re managing traffic flow in a big city.’
For that reason, road operators are not considering using commercially available cellular networks to support their initiatives. In addition, for many fixed connections are impractical because of the cost of connecting each traffic light or sign gantry to wired capacity.
‘Do they really want to rely on a third party network to do something this critical?’ asks Mokrani. ‘These technologies do offer some value because they are very cheap to use; they’re fine for monitoring pollution, but not for anything mission critical such as the timing of traffic lights.’
The smart road concept is relatively new, but growing concern over environmental pollution is seeing road operators having to enable government policies relating to taxation and tolling.
In France, for example, an eco tax on large lorries is to be introduced, which will require almost 900,000 lorries to be equipped with telematics that will communicate with road infrastructure to account for the mileage each lorry has done and enable taxation to be applied accordingly. The aim to generate €1bn in tax revenue and payment will be part of the system, so it has to be certified as secure.
‘The highway company will distribute the in-vehicle equipment which will be based on 2G cellular technology and GPS within the vehicles,’ explains Olivier Beaujard, vice president of market development at M2M module provider Sierra Wireless.
Another factor to consider is that many applications don’t require huge bandwidth from the network that supports them. Capacity demand can range from 2 megabits per second up to 20 or 30 megabits for many sensor-based activities. However, when ANPR (Automatic Number Plate Recognition) or video content is involved, far higher bandwidth is required.
‘3G is not in use very much because the data to be sent is very small,’ says Beaujard. ‘We see 3G as being more of an opener for 4G which can support networks of cameras and surveillance of areas. There will be a lot of data to upload from those applications and 4G will be able to handle that at low latency.’
For others, it’s hard to see the need for greater capacity. ‘We need a less than text strength signal to move the data around,’ says Giles Margerison, the UK director of TomTom Business Solutions, which provides a range of telematics services to business users that typically combine GPS data with data collected from the vehicle.
‘We use GPRS because it’s about the most reliable coverage available, it’s not open to the vagaries of 2G or 3G. GPS always works so we can buffer data if there’s an interruption to the GPRS coverage.’
TomTom’s system plugs into the onboard diagnostics system to gather data on how the vehicle is being driven, how long it is idle and can be used to give the driver feedback to improve economy or drive more safely. The benefits can be substantial (see box above).
As more vehicles hit the roads with wireless and M2M capability embedded, the possibilities increase both for fleet operators and road companies. ‘In the future, it is entirely possible that all vehicles will have network connectivity,’ says Curran.
‘This allows them to receive firmware or software updates and synchronisation over the local or home network of music or GPS data. It is only a small step for much of the telemetry data associated with that vehicle to also be uploaded so as to allow a city to optimise traffic management.’
Georgia Department of Transportation
InfiNet Wireless has installed a high capacity point-to-point wireless network for Georgia Department of Transportation (GDOT) in the USA, which wanted to improve traffic light timing in order to improve traffic flow and cut vehicle emissions.
The network, which uses MIMO technology to link key sites such as traffic lights and feed the data back for analysis and management, has enabled GDOT to fine tune traffic flow. Across the entire region, delays are down by 6% and subsequent fuel consumption has dropped by an estimated 700,000 gallons, saving motorists $19m – $16.8m in time and $2.3m in fuel.
Zenith Hygiene Group delivers cleaning and hygiene products to customers across the UK using its fleet of 61 lorries. In order to make its logistics processes more efficient, to save time, fuel and money, it researched various satellite navigation and tracking systems and chose a system offered by TomTom.
The system relies on a Vodafone Sim card and GPRS connectivity to the head office, so vehicles can be tracked in real time. This shows where they are, where they are going and how fast, and how far they’ve travelled. It also gives data on driver behaviour such as engine idling and the time taken to make deliveries.
A study by independent research firm, ERM, found an estimated yearly net saving of nearly 600 tonnes of CO2 per year in comparison to before the system was deployed. This is equivalent to a 28% saving in CO2 emitted by the delivery lorries. It is also the same as the amount of CO2 emitted in 1,000 lorry trips from London to Manchester and back.
In financial terms, it is estimated that if Zenith continues at its current level of fuel efficiency, it could save in the region of £218,000 per year on fuel costs, with a further potential £50,000 on reduced maintenance costs. In addition, it has saved a further £68,000 per year on insurance premiums.