Scania Truck Safety Systems Explained: How Modern Driver Assistance Technology Works
Modern trucks are packed with cameras, radar, electronic safety systems and driver-assistance technology, but how many drivers really understand what each one does? In Part 3 of our Scania road-safety series, we look at the major safety and driver-support systems available across today’s Scania truck range, how they work and, more importantly, how they can help the driver maintain control or avoid a crash.
Scania R660 B-double travelling on an Australian highway
Climb into a new truck today and, as soon as you turn the key the truck starts checking itself. A welcome screen appears, messages scroll across the dash and somewhere behind the scenes cameras, radar sensors and electronic control units are all talking to one another. That is good news for the driver, but the important question is no longer simply what safety systems are fitted. It is understanding what each one is doing, when it is active and how it may respond when conditions suddenly change.
Advanced Emergency Braking, adaptive cruise control, lane-departure warning, blind-spot monitoring, stability control and vulnerable-road-user detection are now familiar terms, but the safety story goes much further. Modern Scania trucks can also incorporate steering assistance, driver monitoring and speed-management systems, while the driver has access to controls that help set the truck up for the road, load and terrain.
Some systems simply warn the driver, while others can assist with steering, braking or speed control. There are also systems that sit quietly in the background and may only become obvious when a dangerous situation starts developing. The benefit of all this technology is significant, but it works considerably better when the person behind the steering wheel understands what the truck is doing and why.
Rather than simply working through another list of acronyms, which the transport industry already produces with considerable enthusiasm, it is probably more useful to look at what a modern Scania is actually doing around the driver from the moment the truck is started through to the point where the electronics may have to intervene.
We will also touch briefly on the role of the transmission and driveline, but Opticruise modes, engine braking, retarder integration and terrain management deserve an article of their own. Once you start looking at the way those systems interact with the truck, the load and the road, it quickly becomes a much larger subject.
Modern Scania cabs bring an increasing number of vehicle functions, settings and driver-support systems together through the central display.
Using adaptive cruise control
Adaptive cruise control becomes much more useful once you understand what it is actually trying to achieve.
Like conventional cruise control, you select the road speed you want the truck to maintain. The difference is that adaptive cruise control is also watching the traffic ahead. If the road is clear, the truck maintains your selected speed. If you begin catching a slower vehicle, the system recognises that the gap is reducing and progressively lowers your speed to maintain the following distance you have selected.
Once that vehicle accelerates, moves away or changes lanes, the Scania can begin increasing speed again until it returns to your original cruise setting.
One of the most useful controls the driver has is the following-distance setting, because there is no single gap that suits every situation. On an open highway in good weather, with light traffic and good visibility, you might comfortably use a medium or longer setting while still maintaining a sensible safety margin.
The situation changes in dense traffic. On Brisbane’s Bruce Highway or Melbourne’s Monash Freeway during peak hour, for example, leaving an enormous space ahead of the truck can result in car after car moving into the gap. The adaptive cruise control then recognises each new vehicle and slows the truck again to rebuild the selected following distance, at which point another motorist spots the newly created opening and decides it looks rather inviting.
The result can be a truck that is constantly slowing and accelerating even though the surrounding traffic is moving reasonably steadily. Selecting a sensible shorter following-distance setting in those conditions can help the truck flow more naturally with the traffic around it.
Right-hand-drive Scania truck cab configured for Australian operation
The system can also follow traffic down to a standstill. If the vehicle ahead slows and stops, suitably equipped trucks can progressively reduce speed and bring the truck to a stop as well, which can make a considerable difference to driver workload in heavy traffic.
However, the driver still needs to stay well ahead of the electronics in anticipating what is developing beyond the vehicle immediately in front. If you are travelling at 100km/h and catch a vehicle doing 90km/h, the adaptive cruise control can see that you are closing the gap and respond accordingly. If you decide to overtake, indicate and move into the clear lane, the system will recognise that the slower vehicle is no longer directly ahead and begin accelerating the truck back towards the selected cruise speed.
What it cannot necessarily do is understand everything that is developing further up the road. Traffic lights, intersections, merging vehicles, roadworks, hills and changing traffic conditions may all require the driver to make a decision before the adaptive cruise control does.
Road conditions matter as well. If the surface becomes wet, icy or slippery, or visibility deteriorates significantly, the better option may be to switch cruise control off altogether and control the truck’s speed yourself. The radar can measure the vehicle ahead and adjust the speed accordingly, but it cannot create additional tyre grip or judge every subtle change in the road surface in the same way an alert driver can.
Used properly, adaptive cruise control is a very effective workload-reduction tool that can contribute to smoother driving, better fuel economy and improved safety. The best way to think of it is as another set of electronic eyes constantly measuring what is happening ahead, while the driver remains responsible for deciding how the truck should be driven.
Steering wheel-mounted controls allow drivers to manage key functions without distraction.
Keeping the truck in its lane
Lane-departure systems are another safety aid that become much more useful once you understand what the truck is actually watching.
A forward-facing camera reads the lane markings and continually monitors where the truck is positioned between them. If the vehicle begins drifting towards a line without the driver deliberately changing lanes, the system can issue a warning. Depending on the equipment fitted, that may be an audible or visual alert, while more advanced systems can also provide gentle steering assistance to help guide the truck back into the lane.
The important part of that description is that the movement is unintentional. If you indicate and deliberately change lanes, the truck recognises that you are carrying out a planned manoeuvre. The warning is intended for those occasions when the truck begins wandering towards the centreline or edge of the road without the driver meaning to go there.
On a good highway with clear lane markings, you should not be hearing lane-departure warnings very often. If the system starts regularly telling you that you are moving out of the lane, it is worth resisting the temptation to immediately decide the electronics are being a nuisance. The truck may be telling you something useful.
You may be distracted, becoming tired or simply allowing your concentration to wander. If the system repeatedly activates on a road where the lane markings are clear, take some notice of it, because it may have detected a change in your driving before you have consciously recognised it yourself.
Where lane-departure systems can become frustrating is on roads that were never really designed with this kind of technology in mind. A narrow country road is a good example. You may deliberately move closer to the fog line to give an approaching heavy vehicle more room, or adjust the truck’s position through a tight bend.
Lane-departure systems rely on clearly defined road markings, which is why narrow roads, roadworks and inconsistent line marking can sometimes challenge the technology.
Roadworks can be even more entertaining, particularly where temporary lane markings cross old markings or where several generations of line marking remain visible in various stages of being painted over. The camera may suddenly be presented with several different opinions about where the lane actually is, none of which appear particularly convincing.
That is where driver judgement becomes important. If you are on a road where you are constantly and deliberately running close to lane markings, and the system repeatedly warns or tries to correct something you are doing intentionally, switching the lane assistance off may be the sensible option.
The same applies to Lane Keep Assist. Scania developed the system primarily for intercity motorway driving, where lane markings are clear and the road geometry is relatively predictable. Under those conditions it can reduce workload by helping keep the truck correctly positioned in the lane. On narrow roads, through roadworks or anywhere the markings are poor or misleading, the driver may prefer to steer the truck without the system continually trying to assist.
There is, however, an important difference between switching it off because the road conditions make the system unsuitable and switching it off simply because you do not like being warned. If the road has good markings and the system is regularly activating, it is worth asking yourself why before reaching for the switch.
Lane-departure warning is not there to drive the truck for you. Most of the time it should sit quietly in the background, and when it does speak up the sensible response is to work out whether the system has misread the road or whether your own position has started to drift.
Scania truck with graphic illustrating forward safety monitoring systems
Watching the blind areas
One of the fundamental challenges with any heavy vehicle is visibility. The truck is large, the driver sits high and, despite the collection of mirrors, windows and cameras around a modern cab, there are still areas close to the vehicle that can be difficult to monitor continuously.
Traditional mirrors have improved enormously, and camera-monitor systems are becoming increasingly common. These can provide standard, wide-angle and zoomed views while also reducing some of the obstruction created by large external mirror housings.
Even so, there is still no substitute for maintaining awareness of what is around the truck. Blind-spot and vulnerable-road-user detection systems add another layer of protection by using radar, cameras or other sensors to monitor areas beside the vehicle and warn the driver when a cyclist, pedestrian or vehicle moves into a potentially dangerous position.
The obvious example is a cyclist travelling beside the passenger side of the truck as you approach an intersection. The driver should already be looking for them, but urban traffic can be busy and there may be several things demanding attention at once. An additional warning from the truck may provide the extra second needed to stop a dangerous situation developing into a collision.
These systems are not just useful in city work either. Long-haul trucks still enter towns, fuel stops, depots, loading areas and workshops where pedestrians, cyclists, forklifts and cars can suddenly appear close to the vehicle.
The technology does not replace normal observation. Drivers still need to use the mirrors or camera displays and maintain awareness of what is happening around the truck. What the system provides is another layer of observation when the driver already has plenty to keep an eye on.
Digital rear-view mirrors give the driver a clear view along the side of the truck while reducing some of the obstruction created by conventional exterior mirror housings.
Drivers need to understand how the systems work together
Perhaps the biggest change in modern truck safety is not any single piece of equipment, but the way all these systems increasingly work together.
Cameras, radar, braking systems, steering assistance, cruise control and lane monitoring do not necessarily operate as a collection of completely independent devices. They can share information and, depending on the truck, one system may influence how another responds.
That means driver familiarisation now needs to go further than simply recognising a warning light or knowing where the switch is located. Drivers should understand what systems are fitted, when they are active, what they are monitoring and roughly how the truck is likely to respond if a situation begins to develop.
For example, a forward-facing camera or radar installation may be helping the truck monitor following distance, recognise lane position or support an emergency-braking function. If the sensor cannot see properly because of heavy rain, dirt, insects or some other obstruction, several functions may be affected at the same time.
The same applies to poor road markings. If the lane camera is struggling to identify where the road markings are, any system relying on that information may also have reduced capability.
This becomes particularly important when drivers change vehicles. An experienced driver may climb into a truck with unfamiliar controls, different warning thresholds or a different level of intervention from the truck they normally drive.
Years of experience behind the wheel are enormously valuable, but they do not automatically tell you how an unfamiliar safety system is going to behave. One truck may simply issue a warning, while another may also provide steering or braking assistance.
It is much better to discover those differences while sitting in the yard with the handbook or familiarisation information than while something unexpected is unfolding at highway speed.
A few minutes spent understanding how the systems work together before leaving the yard can prevent a considerable amount of confusion later.
Scania’s new digital rear-view camera system replaces conventional mirrors and contributes to both improved visibility and lower aerodynamic drag.
Include the safety systems in the pre-start
Modern technology has also added a few new items to the daily pre-start inspection.
Drivers are already accustomed to checking tyres, lights, mirrors, couplings and the general condition of the truck, but cameras, radar sensors and other electronic safety equipment now deserve the same attention.
A forward-facing camera trying to look through a dirty windscreen cannot work at its best, and neither can an external camera covered in mud, dust or insects. The same applies to radar sensors and other external equipment that rely on having a clear view of what is happening around the vehicle.
As part of the pre-start, check that camera lenses and sensor areas are clean and unobstructed, and that mirrors are clean and correctly adjusted. Once the truck is started, take notice of any warning or fault messages rather than simply clearing the screen and heading for the gate.
Where fitted, reversing and surround-view cameras should also be checked before they are needed. Finding out the reversing camera has failed when you are halfway into a tight loading area is considerably less convenient than discovering it while the truck is still parked in the yard.
Exactly what needs to be inspected will vary between vehicles, but the principle is simple. Cameras and sensors are now working equipment, just like mirrors and lights, and they need to be kept in a condition where they can do their job properly.
The driver is still the most important part of the system
Modern trucks can monitor closing speeds, watch lane position, detect vulnerable road users, assist with steering and, in some situations, begin braking before the driver has responded.
That represents an extraordinary level of assistance compared with the trucks many drivers started their careers in, but none of it reduces the importance of good driving. In fact, these systems work best when they are supporting a driver who is already doing the fundamentals properly.
That means looking well ahead, maintaining a safe following distance, adjusting speed early, watching the mirrors and camera displays and constantly anticipating what other road users may do next. The electronics are there to provide another layer of information and protection when something unexpected happens.
That is probably the best way to look at all of these systems. They are not there to replace the professional driver, and they certainly do not relieve the driver of responsibility for what the truck is doing. Their value is in helping the driver make better decisions and, when necessary, providing another opportunity to avoid a crash.
The safest journey will usually be the one where the driver sees the developing problem first, makes a small adjustment to speed or road position and simply carries on. If the truck never needs to issue an emergency warning, apply the brakes or make a corrective intervention, that does not mean the technology was unnecessary. It means the driver was reading the situation early enough that the electronic safety net never had to catch them.
And really, that is exactly how the system is supposed to work.
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