Recognition distance of pedestrian traffic signals by individuals with low vision

Williams, Michael D.; Houten, Ron Van; Blasch, Bruce B.

doi:10.1682/jrrd.2005.02.0040

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…Photos were digitally manipulated such that in each presentation of a given crossing the location of the pedestrian signal, as well as the interval and countdown information being displayed, was variable. Stimuli were created and selected such that the prevalence of Walk and Don’t Walk intervals was equal and the prevalence of the various countdown values (1–12) was nearly equal.…”

Section: Methodsmentioning

confidence: 99%

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Perception of Pedestrian Traffic Signals by Pedestrians with Varying Levels of Vision

Scott

Atkins

Bentzen³

et al. 2012

Transportation Research Record: Journal of the Transportation R

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This study evaluates the usability of pedestrian signals by persons with varying visual acuities under different conditions of symbol size, crossing length and type of background behind the pedestrian signal. While viewing photographs presented on a computer monitor under unimpaired viewing conditions (approx. 20/20 visual acuity) and under simulated visual impairment (approx. acuities of 20/100 and 20/300), participants attempted to determine the pedestrian phase (Walk or Don’t Walk) and to report the number presented by the countdown timer display. Performance on the phase discrimination task by those with simulated 20/300 acuity and with 9 and 12 in. high symbols often resulted in performance which was little better than chance despite a highly controlled environment (i.e., no moving vehicles or environmental distractions) and signals which were subjectively in excellent working condition and of high visibility (i.e., good luminance/contrast, no glare). Reading the countdown display was essentially impossible. Participants with simulated 20/100 acuity were rather successful with regards to phase identification – averaging better than 87% correct under all stimulus conditions – but room for improvement exists as compared to performance in the 20/20 condition. Reading the countdown display was difficult for participants with simulated 20/100 acuity – averaging between 6.5% and 58.5% correct under the various stimulus conditions. The effect of different backgrounds on the usability of the signals, as well as the implications of the findings with regards to signal size and crossing length on the current signals standards, are discussed.

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Section: Methodsmentioning

confidence: 99%

“…Two recent projects have considered recognition distance of pedestrian signals of different shapes by pedestrians with low vision (11, 12). In both studies, research was conducted in daytime with relatively uncluttered backgrounds, and with signals always in the same location.…”

Section: Introductionmentioning

confidence: 99%

Perception of Pedestrian Traffic Signals by Pedestrians with Varying Levels of Vision

Scott

Atkins

Bentzen³

et al. 2012

Transportation Research Record: Journal of the Transportation R

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“…[21] Michael D. Williams, Ron Van Houten, and Bruce B. Blasch researched the recognit ion distance of pedestrian traffic lights by individuals wit h low vision. [22] For the pedestrian, only red and green lights need to be classified.…”

Section: Introductionmentioning

confidence: 99%

Real Time Traffic Light Recognition System for Color Vision Deficiencies

Kim

Yang

2007

2007 International Conference on Mechatronics and Automation

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Color blindness can be challenging as well as cumbersome for a person especially when driving a vehicle. In this paper, a real time traffic light recognition system based on computer vision will be described that improves the safety of drivers who are color-blind. The system consists of a digital video camera and a portable PC that helps the system to detect and track red, green, and yellow traffic lights. The paper will explain how the RGB component adjustment, thresholding algorithm, and median filter are used to recognize traffic lights. In order for the system to handle illumination changes by weather and time, a simple adaptation method has been developed. For future use, the portable system has been simplified since audio has been added to the current system, which helps to inform the traffic light the driver is color-blind.

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Countdown Pedestrian Signals and Low-Vision Pedestrians

DeLaere

Houten

Morgan

et al. 2015

Transportation Research Record: Journal of the Transportation R

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The countdown pedestrian signal (CPS) has been shown to be more intuitively understandable than other signals in the way that it communicates the amount of available crossing time at an intersection. The improved comprehension may result in better levels of service to pedestrians at signalized intersections. Survey research has shown that the traditional flashing don't walk (FDW) signal is poorly understood, with low levels of pedestrian comprehension. By contrast, comprehension of the CPS tends to be much higher: between 86% and 100%. The study reported here examined how well low-vision pedestrians could determine how to respond and when to cross with the use of a CPS alone and with a combination of CPS and FDW at 12-m (40-ft) and 30.5-m (100-ft) crossings. The results showed that low-vision pedestrians often found it difficult to determine the signal phase at a relatively broad crossing, but the removal of the FDW from the display had no negative impact on the decision to cross during the pedestrian clearance phase.

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Recognition distance of pedestrian traffic signals by individuals with low vision

Cited by 3 publications

References 8 publications

Perception of Pedestrian Traffic Signals by Pedestrians with Varying Levels of Vision

Perception of Pedestrian Traffic Signals by Pedestrians with Varying Levels of Vision

Real Time Traffic Light Recognition System for Color Vision Deficiencies

Countdown Pedestrian Signals and Low-Vision Pedestrians

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