Biomedical subjects

Thomas J Triggs

Publications and source records attributed to Thomas J Triggs.

7 recordsLinked to original sources

PubMed2005

Driver distraction: the effects of concurrent in-vehicle tasks, road environment complexity and age on driving performance.

This paper presents the findings of a simulator study that examined the effects of distraction upon driving performance for drivers in three age groups. There were two in-vehicle distracter tasks: operating the vehicle entertainment system and conducting a simulated hands-free mobile phone conversation. The effect of visual clutter was examined by requiring participants to drive in simple and complex road environments. Overall measures of driving performance were collected, together with responses to roadway hazards and subjective measures of driver perceived workload. The two in-vehicle distraction tasks degraded overall driving performance, degraded responses to hazards and increased subjective workload. The performance decrements that occurred as a result of in-vehicle distraction were observed in both the simple and complex highway environments and for drivers in different age groups. One key difference was that older drivers traveled at lower mean speeds in the complex highway environment compared with younger drivers. The conclusions of the research are that both in-vehicle tasks impaired several aspects of driving performance, with the entertainment system distracter having the greatest negative impact on performance, and that these findings were relatively stable across different driver age groups and different environmental complexities.

Accidents, Traffic↗

PubMed2005

Forward/up directional incompatibilities during cursor placement within graphical user interfaces.

Within graphical user interfaces, an indirect relationship between display and control may lead to directional incompatibilities when a forward mouse movement codes upward cursor motions. However, this should not occur for left/right movements or direct cursor controllers (e.g. touch sensitive screens). In a four-choice reaction time task, 12 participants performed movements from a central start location to a target situated at one of four cardinal points (top, bottom, left, right). A 2 x 2 x 2 design varied directness of controller (moving cursor on computer screen or pen on graphics tablet), compatibility of orientation of cursor controller with screen (horizontal or vertical) and axis of desired cursor motion (left/right or up/down). Incompatibility between orientation of controller and motion of cursor did not affect response latencies, possibly because both forward and upward movements are away from the midline and go up the visual field. However, directional incompatibilities between display and controller led to slower movement with prolonged accelerative phases. Indirect relationships between display and control led to less efficient movements with prolonged decelerative phases and a tendency to undershoot movements along the bottom/top axis. More direct cursor control devices, such as touch sensitive screens, should enhance the efficiency of aspects of cursor trajectories.

Adult↗

PubMed2004

Perceptual lane width, wide perceptual road centre markings and driving speeds.

The possibility that driving speeds could be reduced through the use of lane delineation was explored. Using a high-fidelity driving simulator, 28 experienced drivers were measured on seven two-lane rural roads with lane widths of 3.6, 3.0, or 2.5 m, and with either a standard centreline (control), a wide painted hatched road centre marking, or a wide white gravel road centre marking. Driving speeds were reduced on the narrowest lane width road, and further reduced on straight road sections that contained the centre marking with painted hatching. It was concluded that the narrow lane width increased steering workload and reduced speeds through a speed-steering workload trade-off, whilst the hatched road centre marking enhanced peripheral visual speed perception, leading to higher speed estimations and slower speeds. Therefore, narrowing the lane width below 3.0 m by using a painted hatched road centre marking should be an effective way to reduce driving speeds.

Acceleration↗

PubMed2004

The effects of a nap opportunity in quiet and noisy environments on driving performance.

While napping has previously been shown to alleviate the effects of sleep loss, before advocating the use of naps in transport accident campaigns it is necessary to consider whether a nap opportunity in a noisy uncomfortable environment can produce the same benefits as a nap opportunity in conditions that are conducive to sleep. To examine this, eight participants drove a driving simulator for 50 min at 11:00h on three different test days. The simulator used has previously been found to be sensitive to the effects of sleep loss, alcohol consumption, and time of day. All three sessions were conducted after one night of sleep loss. Prior to driving during each session the participants either had a 60 min nap opportunity in a quiet or noisy environment, or no nap opportunity. Driving performance and reaction time while driving were measured, as were subjective sleepiness and ratings of sleep quality. No significant benefits of nap opportunities on driving performance were found. Levels of subjective sleepiness were not affected by the nap opportunity condition; however, sleep was rated as more refreshing and restful after a nap in a quiet environment compared to noisy environment. The measures of effect size reported suggest further research is required to unequivocally test the effects of nap opportunities on driving ability.

Accidents, Traffic↗

PubMed2003

The effects of the opioid pharmacotherapies methadone, LAAM and buprenorphine, alone and in combination with alcohol, on simulated driving.

While methadone is currently the primary pharmacotherapy used in the treatment of heroin dependence in Australia, levo-alpha-acetyl-methodol (LAAM) and buprenorphine are new pharmacotherapies that are being examined as alternatives to methadone maintenance treatment. The aim of this research is to consider the effects of the methadone, buprenorphine and LAAM, as used in maintenance pharmacotherapy for heroin dependence, upon simulated driving. Clients stabilised in methadone, LAAM and buprenorphine treatment programs for 3 months, and a control group of non-drug-using participants, took part in this study which involved operating a driving simulator over a 75 min period. All participants attended one session without alcohol and one session with alcohol at around the 0.05% blood alcohol level. Simulated driving skill was measured through standard deviations of lateral position, speed and steering wheel angle, and reaction time to a subsidiary task was also measured. While alcohol impaired all measures of driving performance, there were no differences in driving skills across the four participant groups. These findings suggest that typical community standards around driving safety should be applied to clients stabilised in methadone, LAAM and buprenorphine treatment. The findings are important in terms of the widespread implementation of these treatment options in Victoria given that a large proportion of pharmacotherapy clients drive.

Adult↗

PubMed2003

Conflicting directional and locational cues afforded by arrowhead cursors in graphical user interfaces.

Task-irrelevant features of arowhead cursors may generate conflict during cursor placement within graphical user interfaces. Arrowheads can signify location, but also cue direction and feature in optical illusions. To address the influence of conflicting cues, 14 participants used arrowhead cursors (standard, oversized) pointing upward or downward to move to targets (7.5, 15-mm diameter) situated at the top or bottom of the screen. Compatible arrowhead orientation improved response initiation. Cursor size, orientation, direction of motion, and target size interacted during cursor movement. Overshooting occurred for oversized cursors in the direction the arrow pointed for larger targets. Larger compatible arrowhead cursors elicit less efficient cursor positioning movements that are more susceptible to illusory processes, posing implications for design of cursors and graphical user interfaces.

Adult↗

PubMed2002

Driving simulator validation for speed research.

The behavioral validation of an advanced driving simulator for its use in evaluating speeding countermeasures was performed for mean speed. Using mature drivers, 24 participants drove an instrumented car and 20 participants drove the simulator in two separate experiments. Participants drove on roads which contained transverse rumble strips at three sites, as well as three equivalent control sites. The three pairs of sites involved deceleration, and were the approaches to stop sign intersections, right curves, and left curves. Numerical correspondence (absolute validity), relative correspondence (or validity), and interactive (or dynamic) relative validity were analyzed, the latter using correlations developed from canonical correlation. Participants reacted to the rumble strips, in relation to their deceleration pattern on the control road, in very similar ways in both the instrumented car and simulator experiments, establishing the relative validities. However, participants generally drove faster in the instrumented car than the simulator, resulting in absolute validity not being established.

Adult↗