In-car Display Research Articles

Modeling visual sampling on in-car displays: The challenge of predicting safety-critical lapses of control

In this article, we study how drivers interact with in-car interfaces, particularly by focusing on understanding driver in-car glance behavior when multitasking while driving. The work focuses on using an in-car touch screen to find a target item from a large number of unordered visual items spread across multiple screens. We first describe a cognitive model that aims to represent a driver׳s visual sampling strategy when interacting with an in-car display. The proposed strategy assumes that drivers are aware of the passage of time during the search task; they try to adjust their glances at the display to a time limit, after which they switch back to the driving task; and they adjust their time limits based on their performance in the current driving environment. For visual search, the model assumes a random starting point, inhibition of return, and a search strategy that always seeks the nearest uninspected item. We validate the model׳s predictions with empirical data collected in two driving simulator studies with eye tracking. The results of the empirical study suggest that the visual design of in-car displays can have a significant impact on the probability of distraction. In particular, the results suggest that designers should try to minimize total task durations and the durations of all visual encoding steps required for an in-car task, as well as minimize the distance between visual display elements that are encoded one after the other. The cognitive model helps to explain gaze allocation strategies for performing in-car tasks while driving, and thus helps to quantify the effects of task duration and visual item spacing on safety-critical in-car glance durations.

Use of the Backseat Driving Technique in Evaluation of a Perceptually Optimized In-Car Navigation Display

Recently drivers have greatly benefited from new vehicular technologies such as in-car navigation systems, but at the same time they can be easily distracted from those technologies. Consequently, creating displays that balance the communication of information with the attentional demand imposed on the driver is of increasing importance. A set of research has been conducted to minimize the driver’s attentional cost toward the navigational displays while driving. However, accurate evaluation methods to assess the effects of these displays in realistic environments are not yet available. This article introduces the backseat driving technique for high-fidelity, safe, and inexpensive evaluation of interaction with in-car displays. This technique makes use of a real vehicle driving on a real road. As a result it allows for the exploration of some types of research questions using audio, visual, and kinesthetic stimulus at least equal in fidelity to very high-end driving simulators, without requiring such a specialized and expensive facility. Further, it allows for the employment of detailed and fine-grained measures of attentional demand, which cannot be safely used with subjects who are actually driving. Although the backseat driving technique can address only some types of questions and so is not a full replacement for high-realism driving simulators, it may offer a new approach, which augments laboratory, simulator, and real driving for many studies. As a part of the work presented here, the backseat driving technique is used to evaluate a previously developed in-car navigation display—the MOVE system. The technique allowed for new questions to be asked, which were not able to be considered in previous laboratory studies, and for the use of study measures that were only previously able to be used in the laboratory due to driving safety concerns. Specifically, the display was shown to work well when real-world stimulus are used to navigate along a real route, reducing the navigation error rate nearly threefold, and up to sixfold when compared to displays providing more or less contextual information. In addition the display was shown to cut total display fixation time (which is time spent looking away from the road) almost in half in both cases.

Dynamic speed guidance for active highway signal coordination: roadside against in‐car strategies

The effectiveness of signal coordination can be undermined by over-long spacing and different vehicle dynamic characteristics between neighbouring signal intersections in a signalised highway system. This study presents two dynamic speed guidance (DSG) strategies based on the traffic environment and facility deployment to congregate the traffic flow and optimise the arterial coordinated signal control system. One of them is the in-car display for individual guidance, and the other is the roadside display for group guidance. The two DSG strategies are calculated using the rolling horizon approach. A simulation platform that integrates data communication, traffic mobility and DSG application is programmed based on VISSIM, a microscopic simulation model. A section of Cao'an highway is used to assess the efficiency of two DSG strategies. The assessment results show that both the average stops and travel time of arterial vehicles can be optimised with the application of the two DSG strategies. In addition, the in-car strategy provides a significant benefit for on-board unit equipped vehicles, even in a low level of market penetration rate.

Eco-driving Versus Green Wave Speed Guidance for Signalized Highway Traffic: A Multi-vehicle Driving Simulator Study

New in-vehicle systems provide the driver with speed advises through the variable message signs and the use of an in-car display. In this paper, two dynamic speed guidance strategies (green wave speed guidance strategy (GWSGS) and eco-driving speed guidance strategy (EDSGS)) through in-car display were tested. A new multi-vehicle driving simulator platform taking into account drivers interactions was built, and the two strategies for highway system were programmed through the script language provided by Virtools software. To evaluate the effectiveness of the overall strategies, 15 typical drivers were recruited to take part in the speed guidance experiments. It was found that the number of stops is both significantly reduced for the vehicles with the GWSGS and EDSGS. Compared with the vehicles without speed guidance, the fuel consumption and CO2 emissions can be reduced by 25% and 13% under the EDSGS and GWSGS respectively. The eco-driving vehicle's velocity trajectory is smoother than that of the green wave vehicle, and the average compliance rate of EDSGS is higher than GWSGS. The EDSGS showed more benefits than the GWSGS.

Ecological IVIS design: using EID to develop a novel in-vehicle information system

New in-vehicle information systems (IVIS) are emerging which purport to encourage more environment friendly or ‘green’ driving. Meanwhile, wider concerns about road safety and in-car distractions remain. The ‘Foot-LITE’ project is an effort to balance these issues, aimed at achieving safer and greener driving through real-time driving information, presented via an in-vehicle interface which facilitates the desired behaviours while avoiding negative consequences. One way of achieving this is to use ecological interface design (EID) techniques. This article presents part of the formative human-centred design process for developing the in-car display through a series of rapid prototyping studies comparing EID against conventional interface design principles. We focus primarily on the visual display, although some development of an ecological auditory display is also presented. The results of feedback from potential users as well as subject matter experts are discussed with respect to implications for future interface design in this field.

Measuring Distraction at the Levels of Tactical and Strategic Control: The Limits of Capacity-Based Measures for Revealing Unsafe Visual Sampling Models

The control theory of driving suggests that driver distraction can be analyzed as a breakdown of control at three levels. Common approach for analyzing distraction experimentally is to utilize capacity-based measures to assess distraction at the level of operational control. Three driving simulation experiments with 61 participants were organized to evaluate which kind of measures could be used to analyze drivers' tactical visual sampling models and the related effects of distraction while searching textual information on in-car display. The effects of two different text types were evaluated. The utilized capacity-based measures seemed to be insufficient for revealing participants' tactical behaviors or effects of text type. The measures of workload or performance did not indicate reliably the differences found between participants' visual sampling strategies or which text type is better for enabling safer task timing behaviors. Visual sampling measures did indicate effects of text type on participants' tactical abilities. Differences in participants' visual sampling strategies leading to different levels of systematicity in visual behaviors can explain the variances in visual sampling efficiency. Displays encouraging unsystematic glance allocation behaviors were found potentially the most distracting in relation to safe visual sampling of in-vehicle displays.

Aging and Time-Sharing in Highway Driving

Proper time-sharing--visual attention allocation--between the road view ahead and other targets is an essential requirement for safe driving, along with other visual and attentional performance. Earlier on-road research has shown that neurologic problems (Alzheimer disease, brain injury) impair time-sharing during in-car tasks. This study analyzed age effects on time-sharing performance. Thirty participants in three age groups (mean age 22, 34, and 67 years) drove an instrumented car a trip of 350 km and performed an in-car visual search task with either a motor (keying) or vocal response. The frequency and duration of glances at the in-car targets, total time eyes off the road during task, speed, and lateral displacement of the car were recorded. The participants were also tested on a battery of cognitive tasks during the midway break. The elderly used a longer total time looking at the in-car display and they traveled a longer distance with eyes away from the road. The number of long (>2 sec) glances and the car's lateral displacement on the road were larger among the elderly than the young drivers. The difference between the older and younger participants was larger when a motor (keying) response was required. The age effects were mediated by cognitive performance (best by the Trail Making A test) rather than by vision parameters. Older drivers have difficulties in time-sharing in highway driving already at the age of 65 to 70 years.

LISB—An Individual Route Guidance and Information System in Berlin

Publisher Summary The LISB field trial in Berlin started in 1985. There are four groups working on the project: (1) SIEMENS as technical project manager, (2) BOSCH-BLAUPUNKT as industrial partner, (3) the SNV, a nationwide transportation consultancy, and (4) a research team at the Technical University of Berlin. SIEMENS and BOSCH developed the guidance system ALI-SCOUT. While SIEMENS is responsible for infrastructure and hard- and software; BOSCH-BLAUPUNKT cares for the in-car display unit. SNV manages the project on the political side and cares about the test drivers by investigating their attitudes and experiences. The main task of the research team of Technical University, Berlin is to provide the guidance system with all demanded information on the Berlin road network and to create strategies for route guidance. The strategy of the LISB system is based on the first step of a low-penetration concept. It guides the driver on the routes that offer a minimum of individual journey time. The overall system consists of the vehicle equipment, the supplementation of existing traffic control signal installations by infrared transmitters and receivers on the signal masts, the beacon control in the interconnected local controllers, and a central traffic-guidance computer.