交通运输安全中英文对照外文翻译文献
Technology Hand-held wireless device Auditory displays NTSB 1.1 Introduction
The National Transportation Safety Board (NTSB) investigates highway accidents in order to make recommendations to improve highway safety. It is from that perspective that this chapter considers digital signal processing (DSP) for mobile and vehicular systems. Highway safety programs seek to improve safety either by preventing crashes or by increasing crash survivability. US public policy has reached some practical limits in occupant protection and crash mitigation; consequently, new programs, such as intelligent transportation systems (ITS), focus on crash avoidance to improve safety.
exceptions, like stability control systems, technologies for crash avoidance involve the driver as a critical control element in the system’s performance.
This chapter looks at the human factors influences on in-vehicle system designs. 1.2 Highway Safety
The NTSB investigates transportation accidents in all modes of travel—highway, aviation, marine, rail, and pipeline. It is important to realize that the Safety Board is independent of the regulators in the US Department of Transportation (USDOT). That arrangement was carefully constructed to ensure that NTSB investigations and NTSB safety recommendations are unbiased. Many governments around the world have similar organizations.
There are many ways to measure safety, but no one can argue that the bottom line is fatalities. With the exception of highway travel, most modes oftransportation in the United States experience between 700 and 800 fatalities per year.
The number of fatalities in the marine mode each year is approximately 800; the vast majority of those drown in recreational boating accidents.
About the same number of fatalities occurs in rail accidents annually, where majority are trespassers and rail workers, not passengers. In aviation, the average is about 750 fatalities each year, almost all associated with private pilots in small general-aviation aircraft. We also have about a dozen pipeline fatalities each year from gas explosions.
By comparison, the United States had approximately 43,300 highway fatalities and 2.5 million injuries from nearly 6 million crashes last year [1]. Every day, more than 16,000 crashes occur on American highways. With a population of about 300 million, we have over 250 million registered vehicles. The automotive industry is a major economic force in the United States, but highway injuries and fatalities are a drag against that economic engine. Motor vehicle crashes in the United States are estimated to cost more than $230 billion per year [2]. 1.3 Drivers
DSP development work focuses on many different aspects of in-vehicle information systems, including biometric-based authentication; telematics and the associated interface functionality of speech recognition and interaction; autonomous navigation; and personal communications. The technical realization that we can deploy new DSP functionality should always be balanced against the strategic question of ‘‘but should we?’’ Yes, we can develop robust system performance under a variety of environmental conditions and at an acceptable
Recent 5-year averages of annual fatalities by transportation mode are marine 774, rail 806, aviation 752, highway 42,731, and pipeline 14.
B. Magladry and D. Brucecost, but whether we should is a value question predicated on a hierarchy of driving tasks. Will the new system directly improve vehicle control? Will it assistin navigation?
交通运输安全中英文对照外文翻译文献
Will it better inform travelers without negatively impacting driver performance?
The driving environment is defined by many different interactive factors, such as type of vehicle, route, time of day, weather, amount of traffics plus a whole host of activities that go on inside the vehicle—monitoring children, eating, listening to music, making phone calls, etc. Drivers receive a basic licensing test; but they undergo no recurrent training, they receive no medical evaluation, and their education and language skills vary widely. Drivers may be totally inexperienced in their vehicle type, may have conducted no trip planning, and may view driving as secondary to other personal activities in the car. Furthermore, many drivers do not take the time to understand their cars, do not understand how their driving habits affect their safety, and have not read their owner’s manuals.
By and large, driving is a simple task; it must be, because nearly everyone is able to do it. Beginning with inexperienced 16-year-olds all the way through 70- to 80-year-old senior citizens, drivers exhibit a wide range of abilities. However, compared to cars of a generation ago, new vehicles with electronic stability control, moving map displays, bluetooth phone connections, iPod-driven stereos, and passenger video displays present an array of complicated control tasks. As we work to improve and integrate those electronic systems and add functionality to the next generation of highway vehicles, we need to cautiously consider the role of the driver. From a safety vantage point, mistakes can be really costly.
1.4 Attention, Perception, and System Interfaces
The Safety Board has a 50-year history of investigating human performance in transportation accidents. During that time, we have benefited from advances in the sciences of human factors and cognitive ergonomics. The influence of human factors engineering throughout the design process has resulted in early prototyping, task mapping, designing for error management, and exploiting the use of system constraints to enhance safety.
A user-centered design philosophy [3] for in-vehicle system development is becoming the norm, rather than the exception. Designers first ask: what problem are we solving? For in-vehicle systems, that should be a driving problem.
To do this effectively, we need to test the validity of the assumptions that we incorporate into the design—particularly assumptions about the driver and a wide range of behavioral, cognitive, perceptual, and psychodynamic factors.
These individual differences are the very distinctions exploited by DSP driver recognition systems. Drivers are quite often operating beyond their visual or perceptual capabilities in a number of key driving situations, including when overtaking another vehicle, when joining or crossing high-speed roads, or when responding to a number of nighttime situations.
Given the heavy demand that driving places on visual perception, it is prudent to consider alternative display modalities [9]. Unlike the perceptual channel for visual processing, auditory perception is not overloaded during the driving task.
It is, in fact, rarely used [10]. Although auditory display research in the driving domain is somewhat limited, the results are generally positive. Auditory route guidance information has been associated with more efficient driving, as measured by time and distance [11]; auditory route guidance devices result in fewer navigational errors [12]; and drivers have been found to react faster and with fewer errors using auditory information systems instead of visual systems [13].
Deather age defined a set of guidelines for selecting auditory or visual display channels based on the characteristics of the message, the environment, and the task [14]. Using these guidelines, auditory presentation of information is appropriate when messages (1) are simple, short, and temporal in nature;
交通运输安全中英文对照外文翻译文献
(2) require immediate action; and (3) do not have to be referred to later.
However, system interface solutions are not as simple as ‘‘auditory instead of visual’’ information display. The workload associated with attending to invehicle displays depends on the complexity of the message, the interaction requirements necessary to manipulate the system, and the time pressures associated with processing the information. Simply put, there is a cognitive capacity limit that is independent of the perceptual mode. Even if neither the visual nor the auditory perceptual channel is overloaded, the sum of incoming information can create a cognitive processing bottleneck. The result is slowed reaction time, distraction, and a narrowing of focus referred to as ‘‘tunneling’’ that result in missed information.
Researchers have long found it useful to categorize different types of driving activities [15], and we now rather commonly refer to distinctions between control, guidance, and navigation tasks. For example, driving activities associated with travel trip planning and navigation have an elastic window of time that may or may not affect vehicle control. Many aspects of navigation can be deferred until the traffic situation avails an opportunity to consider the information being presented, thereby avoiding the cognitive load of multiple, concurrent activities. However, from a design point of view, it is preferable to constrain the system in ways that do not call on the driver to assign a realtime hierarchy to cognitive demands.
Unlike strategic planning tasks, a different situation exists for in-vehicle systems designed to augment real-time operation and control of the vehicle.
These systems, which provide the driver with information concerning traffic signs, the direction of the next turn, and collision avoidance, are time-critical because they focus on vehicle control activities that have a finite timeframe of performance. Time constraints are an important characteristic to distinguish 4 B. Magladry and D. Brucebetween strategic tasks such as route planning and tactical tasks such as lane tracking [16]. Theoretical research into attention mechanisms and applied research into driver performance indicate that in-vehicle display systems should minimize time-dependent, dual-task situations. This in turn means that temporal distinctions between auditory and visual display should be factored into systems designed to support driving tasks. 1.5 In-Vehicle System Technologies
It is also useful to distinguish between vehicle systems for crash avoidance, which become integral to the operation of the car and often demand very little interaction on the part the driver, and those systems that incorporate the driver as a control loop component. Many manufacturers already offer some form of crash avoidance technology on current car models. These autonomous systems affect stability control, rollovers, lane departures, and rear-end/forward collisions without relying on driver-initiated behavior.
A different category of systems focuses on communicating with the driver. For example, vehicle-centered services, such as remote diagnostics, remote vehicle access, weather sensing, and collision notification, are currently available on many cars. Already, commercial fleet operators use data communications to contact mobile fleets, issue preplanned routes, and notify drivers of scheduled maintenance. In the future, such transmissions will include vehicle software upgrades, malfunction and diagnostic reports, and the capability to order parts and receive recall and service notifications. We will eventually see basic connectivity for the life of the vehicle without the need for ongoing subscription payments, working through a shared message handling utility on behalf of all manufacturers. Highway information for drivers will be as affordable and common as FM radio: the broadcast spectrum for this technology has been identified, and geo-stationary satellites and
交通运输安全中英文对照外文翻译文献
ground-based towers are planned for 2012, with limited rollout by 2009.
Integrated vehicle-based safety systems is a new USDOT vehicle safety initiative to build and field-test integrated crash warning systems to prevent rear-end, lane change, and roadway departure collisions on light vehicles and heavy commercial trucks. These systems are being deployed in cars as well.
1.6 Concerns for Driver Distraction
Human factors engineers know that effective interfaces begin with an analysis of what the person is trying to do, rather than as a metaphor for what the system should display. This distinction between merely providing information and helping with the activity is at the heart of facilitating driver performance rather than causing driver distraction.
1 Improved Vehicle Safety 5A recent naturalistic driving study funded by NHTSA and conducted by the Virginia Tech Transportation Institute is yielding a host of real-world data about driver behavior [17]. That large-scale, instrumented vehicle study included approximately 43,000 h of data on 241 drivers traveling 2 million miles. Early results indicate that visual inattention and engaging in secondary tasks contribute to 60% of crashes. More specifically, looking away from the forward roadway for more than 2 s doubles the odds of being in a crash. Evidence clearly suggests that tasks requiring longer and more frequent glances away from the road are detrimental to safe driving [18]. It should also be noted that even though police reports most certainly understate the magnitude of the problem, inattention has been cited in one-third of all rear-end and lane-change crashes [19].
The 100-car study concluded that dialing a hand-held wireless device increases risk by a factor of 2.8??, but the risk was not just associated with manipulating the phone; talking or listening on hands-free devices increased the risk by one-third (1.3??). This is consistent with earlier research. In 2005, the Insurance Institute for Highway Safety found that Australian drivers using cell phones were four times as likely to be involved in a serious crash as non-users, regardless of whether they used hands-free devices like earpieces or speaker phones.
If we think about in-vehicle auditory displays as talking boxes, continually telling the driver what is visually obvious, then they are synonymous with a nuisance display. Instead, we need to design auditory displays that focus on intelligent selection of information appropriate for the driving task. The future car may be able to acquire information about all 54 million roadside signs, but the driver only needs to know what a sign says when it would affect the safe control of their vehicle or when they specifically request a category of information. Drivers only need to be informed of railroad crossings when trains are active at that crossing. Drivers need not be informed of every cross street along their route of travel, just the one associated with their next turn.
System integration is also an important issue. Different manufacturers makeanti-lock brakes, stability control systems, collision avoidance—and these systems must work in concert to avoid a variety of road hazards. Developers of these technologies must consider how the systems will be used, where displays will be located, how much information is needed, what information has priority, when the systems should be active, and how the systems should function in an emergency. 1.7 Conclusions
Engineering research has made major advances in in-vehicle driver engagement/communication capabilities, but the human factors aspects of the driver interface will be critical to successful implementation of these systems. Drivers, the information that they use, and the environmental conditions in which they operate are necessary components for directly evaluating the suitability of in- 6 B. Magladry and D. Brucevehicle information systems. The functionality of in-vehicle devices