Factors That Affect Drivers’ Perception of Closing and an Immediate Hazard

Author(s):  
Bradley W. Weaver ◽  
Patricia R. DeLucia ◽  
Jason Jupe

Objective To measure the looming threshold for when drivers perceive closing and an immediate hazard and determine what factors affect these thresholds. Background Rear-end collisions are a common type of crash. One key issue is determining when drivers first perceive they need to react. The looming threshold for closing and an immediate hazard are critical perceptual thresholds that reflect when drivers perceive they need to react. Method Two driving simulator experiments examined whether engaging in a cell phone conversation and whether the complexity of the roadway environment affect these thresholds for the perception of closing and immediate hazard. Half of the participants engaged in a cognitive task, the last letter task, to emulate a cell phone conversation, and all participants experienced both simple and complex roadway environments. Results Drivers perceived an immediate hazard later when engaged in a cell phone conversation than when not engaged in a conversation but only when the driving task was relatively less demanding (e.g., simple roadway, slow closing velocity). Compared to simple scenes, drivers perceived closing and an immediate hazard later for complex scenes but only when closing velocity was 30 mph (48.28 km/h) or greater. Conclusion Cell phone conversation can affect when drivers perceive an immediate hazard when the roadway is less demanding. Roadway complexity can affect when drivers perceive closing and an immediate hazard when closing velocity is high. Application Results can aid accident analysis cases and the design of driving automation systems by suggesting when a typical driver would respond.

Author(s):  
Patrick Siebert ◽  
Mustapha Mouloua ◽  
Kendra Burns ◽  
Jennifer Marino ◽  
Lora Scagliola ◽  
...  

This study used both cellular phones and analogue radio to measure driver distraction and workload in a low fidelity driving simulator. Thirty-four participants performed a simulated driving task while using either a cell phone or a radio in conjunction with a secondary task assessing their spare attentional capacity. The results showed that more lane deviations were made during the cell phone and radio tuning use than both of the pre-allocation and Post-allocation phases. The secondary task errors were also higher during both the cell phone and radio tuning allocation phase than the pre-allocation and post-allocation phases. These findings indicate the greater workload load levels associated with the use of telemetric devices. These findings have major implications for driver safety and telemetric systems design.


Author(s):  
Bradley W. Weaver ◽  
Patricia R. DeLucia ◽  
Jason Jupe

Despite ample research on the effects of cell phone conversations on driving, the effects of such conversations on the looming threshold for an immediate hazard are not known. Prior research on the looming threshold for an immediate hazard in the absence of cell phone conversation indicated that the rate of optical expansion at threshold was .006 radians per second. We measured the rate of optical expansion and headway distance at first driving input when participants encountered a stopped lead vehicle while completing a car-following task. Half of them concurrently completed the Last Letter Task, a cognitive task that emulates a cell phone conversation. When compared to the second, third, and fourth scenario exposures to the stopped lead vehicle, the participant’s response on the first scenario exposure occurred when the lead vehicle’s optical expansion rate was relatively smaller and headway distance was larger. However, this effect of scenario exposure occurred only when drivers were engaged in a cell phone conversation. Additionally, participants started to initiate a response when the rate of optical expansion was much lower than the looming threshold reported in previous research. Our results indicate that the first driver input, as operationalized in the current study, does not indicate when drivers first perceive an immediate hazard.


Author(s):  
Ruiqi Ma ◽  
Mohamed A. Sheik-Nainar ◽  
David B. Kaber

This research investigated the effects of an adaptive cruise control (ACC) system, and cell phone use in driving, on a direct objective measure of situation awareness (SA). Subjects drove a virtual car in a medium-fidelity driving simulation and performed a following task. Half of the subjects were required to respond to cell phone calls and all subjects completed trials with and without use of the ACC system. SA was measured using a simulation freeze technique and SA queries on the driving situation. Results indicated use of the ACC system to improve driving task SA under normal driving conditions, and cell phone conversations degraded SA. Results also revealed the ACC system to improve safe driving headway distance. Although the deviations in headway distance from an optimum were greater during cell phone conversations, this did not prove to be significant in terms of performance under normal driving conditions.


2011 ◽  
Vol 20 (1) ◽  
pp. 34-37 ◽  
Author(s):  
David Chapple

Abstract Over the past 20 years, there have been many advances in the computer industry as well as in augmentative and alternative communication (AAC) devices. Computers are becoming more compact and have multiple purposes, such as the iPhone, which is a cell phone, mp3 player, and an Internet browser. AAC devices also have evolved to become multi-purpose devices; the most sophisticated devices have functionality similar to the iPhone and iPod. Recently, the idea of having the iPhone and iPad as a communication device was initiated with the development of language applications specifically for this format. It might be true that this idea could become the future of AAC devices; however, there are major access issues to overcome before the idea is a reality. This article will chronicle advancements in AAC devices, specifically on access methods, throughout the years, towards the transition to handheld devices. The newest technologies hold much promise with both features and affordability factors being highly attractive. Yet, these technologies must be made to incorporate alternate access if they are to meet their fullest potential as AAC tools.


Author(s):  
Zhuofan Liu ◽  
Wei Yuan ◽  
Yong Ma

The distribution of drivers’ visual attention prior to diverting focus from the driving task is critical for safety. The object of this study is to investigate drivers’ attention strategy before they occlude their vision for different durations under different driving scenarios. A total of 3 (scenarios) × 3 (durations) within-subjects design was applied. Twenty-three participants completed three durations of occlusion (0, 1, and 2 s) test drive in a motion-based driving simulator under three scenarios (urban, rural, motorway). Drivers’ occlusion behaviour, driving behaviour, and visual behaviour in 6 s before occlusion was analyzed and compared. The results showed that drivers tended to slow down and increased their attention on driving task to keep safety in occlusion 2 s condition. The distribution of attention differed among different driving scenarios and occlusion durations. More attention was directed to Forward position and Speedometer in occlusion conditions, and a strong shift in attention from Forward position to Road users and Speedometer was found in occlusion 2 s condition. Road users was glanced more frequently in urban road with a higher percentage of attention transitions from Forward position to Road users. While gaze switching to Speedometer with a higher intensity was found on motorway. It suggests that drivers could adapt their visual attention to driving demand and anticipate the development of upcoming situations by sampling enough driving-related information before eyes-off-road. Moreover, the adaptation and anticipation are in accordance with driving situation and expected eyes-off-road duration. Better knowledge about attentional strategies before attention away from road contributes to more efficient and safe interaction with additional tasks.


Author(s):  
R. Wade Allen ◽  
Zareh Parseghian ◽  
Anthony C. Stein

There is a large body of research that documents the impairing effect of alcohol on driving behavior and performance. Some of the most significant alcohol influence seems to occur in divided attention situations when the driver must simultaneously attend to several aspects of the driving task. This paper describes a driving simulator study of the effect of a low alcohol dose, .055 BAC (blood alcohol concentration %/wt), on divided attention performance. The simulation was mechanized on a PC and presented visual and auditory feedback in a truck cab surround. Subjects were required to control speed and steering on a rural two lane road while attending to a peripheral secondary task. The subject population was composed of 33 heavy equipment operators who were tested during both placebo and drinking sessions. Multivariate Analysis of Variance showed a significant and practical alcohol effect on a range of variables in the divided attention driving task.


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