Role of Situational Awareness in Driving Safety - Dissertation Example

?Does situational awareness play an important role to driving safety, how can it be measured and will it be effected by navigation system in cockpit?Situational awareness plays the most crucial role in driving safety, be it a pilot flying a jet, a technician lifting logs with a crane or an ordinary citizen going to his office in a car. The term situational awareness or SA revolves around cognitive processing activities governing the dynamics, event driven activities, and fields that involve multitasking (Banbury & Tremblay, 2004). This term is not specific to driving vehicles or jets; a military expert carrying out a mission in a hostile territory or a player on a football field also use some form of situational awareness. SA plays an important role in driving safety; it is only common sense to understand why and how. When an ordinary people take out their car/bike from the garage of their homes on to the road, they need to be ‘aware’ of their surroundings. They need to do complex calculations about speed, timing and distance in a matter of microseconds to safely drive their vehicle. Without being aware of the ‘situation’ they are more susceptible to accidents, causing injuries to others and to their own bodies. SA becomes even more crucial when the same scenario of driving a car is applied to a person driving a bus full of people. Now this person is responsible for all the people taking a ride in the bus as well as anyone on the road that may get involved in a probable accident. Experts consider air traffic controlling as one of the toughest jobs on earth, and the person sitting in the cockpit of a plane is a part of that job. Flight instructors and seasoned pilots are of the belief that a pilot conducts a safe flight when he has ‘the big picture’, and when things go wrong in the cockpit due to pilot’s mistake, there are some parts missing in the pilot’s ‘big picture’ (Uhlarik & Comerford, 2002). What is this ‘big picture’? Over the years, psychologists and flight experts have turned this concept of big picture into operational definition and experimental paradigm. As with any other scientific term, this ‘big picture’ or the perception of it needs to be measured in some units. For this reason, operational definition converts the concept of SA into measurable empirical units. SA is a psychological paradigm that is not directly observable and ‘operation definition’ is not something defined unanimously; there is considerable disagreement in its definition. SA also has aspects that are similar to other tasks, for instance it also incorporates workload; the greater the workload the more complex the ‘situation’ is to be ‘aware’ of. Moreover there is a direct link between the amount/number of equipment to be assessed and the complexity of SA. This can be exemplified by a simple analogy; a person driving a car early in the morning when the sun has just appeared, is more relaxed as there is hardly any traffic involved. Add the availability of time to the same scenario and the person will not have to do any complex calculations, such as; taking the shortest route or manoeuvring between cars. Compare this to driving during the rush hours, where there is traffic and frustration is hammering on brain nerves, and the boss will get angry if traffic holds up any longer. The driver needs to do all sorts of driving feats to get through the traffic; that is additional work load, the same road turns into a war zone; the SA factors are increased manifolds. SA is very complex in terms of measuring; many myriads of techniques have been developed to measure it but none of these meet the criteria like; sensitivity, unobtrusiveness, selectivity, bandwidth, reliability and diagnosticity (O’Donnell & Eggemeier, 1986). The subject is too complicated that there is not a unanimous consensus on its scope and definition yet. However, the most common definition used over the world about SA is close to the one described at the very start of this paper; “situation awareness is the perception of elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future.” (Endsley, 1995) The above definition can be understood very clearly from the perspective of a pilot sitting in the cockpit of an aeroplane. The perceiving of elements in the environment can be a very difficult task. A pilot needs to be aware of the dials in front of him that tell him; air pressure, altitude, speed, fuel, wind direction, distance from nearby obstructions etc. These elements are the input to the situation that the pilot needs to be aware of. Similarly a racing car driver has elements in his environment that he needs to be aware of. Speed is the most crucial element, and the more detailed perception the driver has, the better he will be able to drive his car. There are curving tracks and road surface, the tire grip, and the speed of the nearby cars trying to get ahead; perception of all of these elements is absolutely necessary for a driver to be ‘aware’ of the situation. The reason for restating the definition is to analyse it from the perspective of a driver and a pilot, but most importantly to understand what critics think about Endley’s definition; not all agree on its entirety offered by Endsley (1995). For instance; Wickens (1992) disagrees with the definition, suggesting that the definition can’t be limited to working memory; the SA needs to incorporate the changing elements as the flight (in relevance to SA of a cockpit) progresses, and the mind’s ability to access this information. Crane (1992) on the other hand focuses his attention to inadequate performance, and proposes that SA is directly associated with expert-level performance (Uhlarik & Comerford, 2002); hence the widely varying epistemology of SA. Particularly relating SA to driving, the chain between the two is called ‘hazard perception’, a subcategory of SA. According to many studies, this is the only aspect of SA that is involved in traffic accidents (Banbury & Tremblay, 2004). And it is easy to understand SA governing the traffic and driving through one major premise; we control speed on the road because of the fear of accidents (hazard). Hence the primary driver of SA (on road) is the perception of hazard. So instead of measuring the SA directly (which is extremely difficult, given the varying definitions and a huge number of environmental elements), the SA of traffic and driving is calculated through hazard perception. To test and measure this perception, the test drivers are subjected to many filmed road situations, and there task is to spot the potential dangers. Research shows that there is a pattern in driving skills that makes a driver more susceptible to crash than others; what is that element? A common misperception is that the more skilled the driver (skilled measured in terms of speed and manoeuvrability), the lesser the likelihood of crashing the vehicle. Studies have shown that it is absolutely incorrect; race car drivers are usually not very good in traffic, in fact experiments showed that they had more accidents than other ordinary drivers (Banbury & Tremblay, 2004). McPherson and McKnight (1976) established a ‘Motorcycle Operators Skills Test’, the objective was to measure driving skills with respect to susceptibility to accidents, but it failed to draw a line between bike riders that were more prone to accidents and those that didn’t have any accidents (Banbury & Tremblay, 2004). Regardless of the above mentioned results, situational awareness remains critical to driving safety; speed and skill are not the only two factors that determine avoidance from accidents. In fact, studies suggest that driving style plays a more important role in hazard perception than driving skill and speeding. Beyond the basic skills needed to control (drive) a vehicle there isn’t much the skills do in terms of avoiding accidents. There is always a situation in accidents where the driver is simply helpless in avoid it. However the events (speed, turns and any manoeuvres) that lead up to that ‘point of no return’ depend a lot on the driving style. Some people are naturally conscious, while others are overly confident, and manoeuvring their vehicle is fun for them. There is no need to completely reject the driving skills in relation to susceptibility of being involved in an accident. As mentioned earlier, hazard perception is the deciding factor (it is a skill) in avoiding accidents on road. In a study conducted on drivers, where the drivers were subjected to filmed traffic situations, it was found that young drivers that failed to perceive the essential features caused more accidents, compared to the group that spotted them (Banbury & Tremblay, 2004). Measuring Situational Awareness Measuring SA depends on the situation; the metrics will be used according to the situation; a submarine navigation vs. military campaign in a battlefield will require different metrics for measurement. However in both situations, the stage of acquisition and the context play a crucial role in measuring SA (Endsley & Garland, 2000). For measuring the final stage of SA acquisition (the desired state), use of eye saccade latencies to govern the impact of expectation on an individual have been proven useful (Stern, Wang & Schroeder, 1995). Measuring SA can vary from physiological measures including heart rate, eye blinks, eye saccade latencies, pupil dilation and EEG to physiological measures such as concurrent memory probe and subjective measurement (Stern, Wang & Schroeder, 1995). SA, no matter which activity it is being measured for, the individual’s age plays a crucial role in it. An 80 year old driver compared to a 30 year old will behave differently toward accidents and hazard perceptions. For instance, blinking of eyes is a measure of SA, then older adults will show variations in eye blinking because of age factor; they will blink more or less depending on the dryness or the level of water in eyes (Rossman, 1989). On a similar note, if heart rate is also a measure of SA, then older adults will score lower due to their comparatively lower heart rate (Lakatta, 1990). There are certain validations that SA measures need to qualify. These validations can be categorized as follows; Construct Validity Relates to the boundaries, the extent to which a test measures SA trait under consideration (Annett, 2002). Predictive Validity It is a measure of how strong the correlation is between the test scores and score on a test criterion (Annett, 2002). Face Validity This is the subjectivity of measuring SA; for instance how accurate the metrics is for measuring the SA subject under consideration (Annett, 2002). It is a check of how accurately something is being measured what it is supposed to be measuring. Concurrent Validity At the end of the test, there is a process of correlating the results with other results extracted from other test measures (Annett, 2002). It is done to establish the correlation between different test results of the same subject. The reason why validation of SA metrics is important because researchers tend to stick to the methods they trust (or think they can), they remain biased in terms of selecting the SA measuring method and choose what they trust instead of testing their method for validation (Stanton & Walker, 2009). So instead of using the method that researchers probably created themselves, they should put their created methodology/metrics to the test of validation. Whenever measuring SA, other than the validation, these key factors must never be neglected; (a) Whenever possible, instead of using one SA measure, try to incorporate as many SA measure as possible, to validate the concurrency (Harwood, Barnett & Wickens, 1988). (b) The participants to SA measure test should be given enough time or the test time duration should be long enough to ensure that the participants get comfortable with the test surroundings (Sarter & Woods, 1991). (c) Researchers should think twice in proposing that SA is the direct cause of behaviour changes (Flach, 1995). Effect by Navigation System: Cockpit Safety Continuing with the hazard perception, there has been immense evince that outside the research domain. To dig deeper there are many unorthodox research tests that can be conducted on how navigation affects cockpit safety. Car driving is a highly interactive dynamic skill. Speeding, judging the distance between two vehicles and calculating how much speed will be required to get through them, overtaking and even waiting at an intersection require masterful perception and situation awareness. It has been already stated that situation awareness is not static; it is continuously evolving when the participant is driving. The car driver is forced to adjust his behaviour according to the situation. Driving is a skill and a test of how a driver adjusts his own understanding according to the situation. And car navigation is a crucial tool in this adjustment. On an obvious note, the better the navigation system, the better the driver will be able to comprehend the situation. Let’s take a look at what today’s automobiles offer in terms of navigational systems in automobiles that can enhance (at least in theory) the situational awareness of a driver in the cockpit. Most of the cars today offer longitudinal control systems, for instance the Adaptive Cruise Control (ACC) (Lundquist, Schon & Gustafsson, 2012). Lateral Control Systems such as lane keeping assistance (LKA) and emergency lane assistant (ELA) and current speed warning have been already released in the market of are under development (Lundquist, Schon & Gustafsson, 2012). Despite of all the advancement in automobile navigation systems, researchers believe that car navigational systems are not of much assistance for car navigation systems (Lundquist, Schon & Gustafsson, 2012). The researchers support this argument by; the satellite assistance that automobiles get (and the drivers to get better awareness) gives accuracy of about 10-20 meters, and for lateral awareness, this range of accuracy is not enough. Even if in future, this range of accuracy is somehow shortened, still the road maps will not be able to aid much; the standard road maps don’t offer enough accuracy to aid lateral awareness. However researchers and car designers are working on making the navigation system better, especially improving the quality of maps; Intensity Based Maps The bin-occupancy filter, is a car navigation device that estimates the distance from a target. Discretized space-state model used for surveillance of a region is the inspiration behind this mapping; each grid cell is a possible vessel to hold a target; a helpful tool for the driver in heightening situational awareness. Occupancy Grip Map For car navigation, an occupancy grid map offers a lot of assistance. It is defined over continuous space, and can be discretized by grid approximation. The OGM or occupancy grip mapping is especially designed for car navigation that maintains consistent size of the map while the car is moving (Lundquist, Schon & Gustafsson, 2012). This is done by discarding the parts that are not needed while creating the new parts in real time. So when the data is noisy or uncertain, OGM is able to assist the driver better than conventional navigation systems. The point is, the use of such maps, lasers, cameras and radar systems is gaining popularity for automobile navigation systems. By using such tools, the sensor data can be used to describe local surroundings of the vehicle, which is extremely useful for a driver sitting in the cockpit of his car. GPS receivers in a car are helpful in comprehending the situation to a certain extent; they are helpful specifically as route guides. When global positioning and the data related to it is sufficient. However the situational awareness is more important when a vehicle positioning is assessed according to its surroundings and not only with the global positioning system. Maps and navigation systems that specifically aid the driver in this perspective increase its localization accuracy, and that is what’s needed. A collisions free trajectory can be developed using such navigational technology; hence increasing the hazard perception. The navigation system in the car cockpit has been developed later than the ones already being used for decades in jets and aeroplanes. In the aviation industry, to maintain a high level of situational awareness is not only critical but one of the most challenging jobs that an air crew faces (Garland, Wise & Hopkin, 1999). Aviation environments are very complex, factors like; aircraft types, phases of flight, nature (mission) of operation, time and resources at hand, and the level of risk involved influence decision-making in aeronautics (Vincenzi, Mouloua & Hancock, 2013). A pilot working with the jet equipment, monitoring the navigation system while flying a jet is exposed to one of the most complicated ‘situations’ that he needs to be ‘aware’ of. For ease in establishing the criterion of use, the term SA will now be used as navigation awareness. There have been many researches on navigation awareness and how it is crucial for a pilot sitting in the cockpit. Andre, Wickens, Moorman and Boschelli (1991) have measured how different displays impact the navigation awareness of a pilot. They conducted an experiment where pilots were given different navigational displays; an inside out display (two-dimensional), a planar outside in display and a perspective outside-in display (Uhlarik & Comerford, 2002). To gauge navigational awareness, four different measures were used; two were focused on measuring the depth and distance, while the other two were focused at pilot’s ability to integrate tasks. Results indicated that participants scored higher on navigational awareness with planar outside-in display, when depth and distance judgement were of prime importance. Perspective displays helped participants more than others when task integration by the pilot was necessary (Uhlarik & Comerford, 2002). Aretz (1991) also conducted experiment on navigational awareness and his results were different than the one discussed above. He chucked in; mental rotation and triangulation, allocating attention resources while navigating and lastly, how different displays of maps affect the navigational awareness (situational awareness). In Aretz’s (1991) experiment, the participants were given questions that required the use of map displays, response time (their ability to assess the hazard and pull the test lever) increased as aircraft’s nose deviated from north, proving that map displays need to be cognitively aligned (Uhlarik & Comerford, 2002). Both the experiments point to one thing, the navigational system, without a doubt, effects the situational awareness (SA) (termed here for convenience as; navigational awareness). The better displays of maps and, navigational assisting equipment need to be cognitively aligned to give a better control to the pilot. Other than better display of maps and other equipment, there are a lot of other factors that contribute to pilot’s situational awareness. A pilot sitting in the cockpit is not running a solo show; he is always working with a team to ensure the safety of his aircraft. Situation monitoring, coordinating of activities and cross-checking of information are crucial to establishing team situational awareness (Salas, Maurino & Allard, 2010). A pilot sitting in a cockpit, even in a flight simulator, faces real time aviation scenarios, the tests and experiments mentioned above hold as much credibility as the real experiment would. There is a direct correlation between heightened situational awareness of the pilot in the cockpit and the success (safety) of the jet. Conclusion Situational awareness plays the most crucial role in driving safely. Without the awareness of the surroundings and how it affects a driver’s own actions is the key to having a safe drive. There are different elements that go in the SA function. It is not merely being aware of factors (like road, traffic lights and nearby cars), it incorporates how these factors behave in space and time. Factors like these don’t remain stationary, they keep on changing, someday it is raining, and the driver needs to hurry to the destination, other days it’s bright and sunny and the road is clear. Which is why SA is doesn’t take place in a still photographic mode, it is continuously changing, and a hint of forecasting, and prediction is also a part of SA for driving safety. As complicated its definition and epistemology is, the same is the case is with its measurement, there isn’t any unit that covers the frame of SA in its entirety, which is why every scholar agrees that SA changes according to the situation, individual and the context. The metrics system of SA constructed for a jet pilot will never be the same used for a taxi driver. However, there are certain rules that researchers and scholar agree that everyone should follow; for instance, try to incorporate as many SA tests as possible while measuring an aspect because this will establish some form of coherence and concurrency between the test results; this is necessary because many researchers like to use their own invented model for measuring SA. The individual matters as much as the metrics system itself. Old people don’t have the same reflexes as young people, even if they spot a hazardous scenario in a perception test, they will probably take longer to react than adults, it’s natural, which is why if SA test is being conducted, individual’s bio data needs to be integrated in the ‘context’ of the test. The participants should also get ample time when going through SA test to get familiar with the environment. SA measurement impacts the SA of a pilot sitting in the cockpit. There are different ways to measure this SA (or navigational awareness). The system that the pilot has, the work load he’s handling and his experience, all come under SA elements. If there is huge work load, navigational displays are wayward or not very friendly, the SA of a cockpit pilot will go down. Pilots need to make decisions in microseconds, their speed of assessing their environment and to calculate what the needles of the navigation system suggest, needs to be sharp enough as not to make a wrong decision due to inability to calculate properly, or a failure to assess the ‘situation’, and crashing the plane due to human error. That is why pilots need helpful displays in the cockpit; the navigation system of the cockpit does effect the measurement of situational awareness. Sources 1. Andre, A. D., Wickens, C. D. Moorman, L. & Boschelli., 1991. 2. Annett, J., 2002. A note on the reliability and validity of ergonomics methods. Theoretical Issues in Ergonomics Science. 3(2). pp. 228-32. 3. Aretz, A. J. 1991. The design of electronic map displays. 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