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Scott A.,Elon University | Atkins K.,Elon University | Bentzen B.,Accessible Design for the Blind | Barlow J.,Accessible Design for the Blind
Transportation Research Record | Year: 2012

This study evaluated 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 signals. While viewing photographs presented on a computer monitor under unimpaired viewing conditions (approximately 20/20 visual acuity) and under simulated visual impairment (approximate 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 symbols 9 and 12 in. high often was little better than chance despite a highly controlled environment (i.e., no moving vehicles or environmental distractions) and signals that were subjectively determined to be 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 in phase identification, and they averaged more than 87% correct under all stimulus conditions. But room for improvement existed compared with performance under 20/20 conditions. Reading the countdown display was difficult for participants with simulated 20/100 acuity; they averaged 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 about signal size and crossing length on the current signals standards, are discussed.


Scott A.C.,Elon University | Barlow J.M.,Accessible Design for the Blind | Guth D.A.,Western Michigan University | Bentzen B.L.,Accessible Design for the Blind | And 2 more authors.
Journal of Visual Impairment and Blindness | Year: 2011

Accurately aligning to a crosswalk is an important component of safe street crossing for pedestrians who are blind. Six alignment cues were evaluated in a simulated crosswalk environment in which the angle of the crosswalk was not always in line with the slope of the ramp. The effectiveness of each cue is reported and implications are discussed. © 2011 AFB, All Rights Reserved.


Salamati K.,North Carolina State University | Schroeder B.,North Carolina State University | Rouphail N.M.,North Carolina State University | Cunningham C.,North Carolina State University | And 2 more authors.
Transportation Research Record | Year: 2011

This paper describes the development and implementation of the conflict-based assessment of pedestrian safety (CAPS) methodology for the evaluation of pedestrian accessibility at complex intersections. Significant research has explored pedestrian access to modern roundabouts and other complex intersections, and a significant focus has been placed on accessibility for pedestrians who were blind. A majority of these studies relied on actual street crossings by study participants under the supervision of a trained orientation and mobility specialist. These crossing studies quantified risk from a measurement of intervention events, in which the orientation and mobility specialist had to physically stop the participant from crossing. Although such studies provide useful data on the crossing risk at a particular intersection, street crossings can be dangerous to the study participants and are time-consuming and expensive to conduct. The CAPS method emphasizes the use of conflict-based safety factors to quantify risk in a framework compatible with indicator studies. This method relates pedestrian crossing decisions to advanced measurements of vehicle dynamics to estimate lane-by-lane conflicts and identifies the grade of conflict on the basis of a five-criterion rating scale. The CAPS framework was applied to a study of crossings by blind pedestrians at a multilane roundabout. The resulting risk scores were calibrated from the actual orientation and mobility interventions observed during the study. The calibrated CAPS framework correctly matched all (high-risk) orientation and mobility intervention events and further identified other (lower-risk) pedestrian-vehicle conflicts. The CAPS framework provides a more efficient, objective, and consistent safety assessment of pedestrian crossings in a research context, without the need for pedestrians to step into the roadway.


Scott A.C.,Elon University | Bentzen B.L.,Accessible Design for the Blind | Barlow J.M.,Accessible Design for the Blind | Guth D.,Western Michigan University | Graham J.,Graham Rehabilitation Services
Transportation Research Record | Year: 2014

Research has demonstrated that accessible pedestrian signals (APS) with push button-integrated speakers increase push-button use and increase the likelihood of starting to cross during the walk interval by pedestrians who are blind. However, consistently positive effects on locating the crosswalk or establishing or maintaining an accurate heading for crossing have not been found. Attempts have recently been made to configure ACS to provide better audible information for these wayfinding tasks. A configuration that has been shown to improve heading accuracy provides audible tones from a speaker at the destination corner before the walk interval (to assist with establishing heading) and during the flashing "Don't Walk" interval (to assist with maintaining heading). Major concerns are that beaconing information may he ambiguous or misleading and result in dangerous crossing behavior at intersections where buildings create echoes of audible signal information and where beacons for multiple crosswalks might be active simultaneously. This study evaluated the effects of a beaconing APS system on pedestrian crossing behavior at an acoustically complex intersection and with multiple beacons sometimes concurrently active. Eighteen participants who were totally blind attempted a total of 216 crossings under three conditions. The results revealed no evidence that participants were distracted or were misled by concurrent beaconing information coming from a corner other than the target destination. Moreover, despite an acoustically complex environment, the beacon led to improved wayfinding performance in some conditions and showed no evidence of having any deleterious effects.


Barlow J.,Elon University | Scott A.,Elon University | Bentzen B.,Accessible Design for the Blind | Guth D.,Western Michigan University | Graham J.,Graham Rehabilitation Services
Transportation Research Record | Year: 2013

This research extends the results of laboratory research on wayfinding at intersections for pedestrians who are blind. Standard accessible pedestrian signals (standard APS), a prototype beaconing APS, and a raised guide strip were evaluated for their ability to assist in establishing and maintaining a heading for street crossings. Experiments were conducted at large, complex signalized intersections in Alpharetta, Georgia; Austin, Texas; and Towson, Maryland. Both the guide strip and the beaconing APS resulted in more accurate street crossing performance than standard APS with respect to alignment (i.e., initial heading) accuracy, rates of being within the crosswalk, distance from the center of the crosswalk at various points during crossing, and the likelihood of being well outside the crosswalk [6 ft (2 m) or more]. For the most part, performance with the guide strip or the beaconing APS was equivalent. Limitations and additional concerns with respect to these two treatments are discussed.


Scott A.,Elon University | Swenson L.,Elon University | Bentzen B.,Accessible Design for the Blind | Barlow J.,Accessible Design for the Blind
Transportation Research Record | Year: 2013

This study evaluated the effect of visual pedestrian signal displays on the ability of persons with reduced visual acuity to accurately and confidently identify the pedestrian interval. While watching video clips of actual intersections presented on a 42-in. monitor under simulated visual impairment, participants attempted to determine the pedestrian interval ("Walk," flashing "Don't Walk," or steady "Don't Walk") and provided confidence ratings for each judgment. Participants in Experiment 1 experienced simulated acuities of 20/70, 20/100, and 20/200; participants in Experiment 2 experienced approximate acuities of 20/20, 20/50, and 20/300. The study made a critical comparison of two methods of signaling the pedestrian change interval (i.e., flashing "Don't Walk"): (a) simultaneous presentation of a countdown and a flashing upraised hand symbol and (b) a countdown-only display without the flashing upraised hand. With the exception of performance in the 20/300 vision category, participants' accuracy on the interval discrimination task was, overall, rather high. However, under simulated visual impairment of 20/70 or worse, participants' success in correctly determining the pedestrian interval was, on average, 21.5 percentage points lower for the countdown display presented without the flashing upraised hand than for the countdown display with the upraised hand. The participants' average reported confidence in their judgment was also lower for the countdown-only condition, and their interval judgment response times also showed a negative effect of the countdown-only display. Implications of the study findings with regard to visual impairment and signal displays for the pedestrian change interval are discussed.


Gattis J.,University of Arkansas | Gluck J.,AECOM Technology Corporation | Barlow J.,Accessible Design for the Blind | Eck R.,West Virginia University | And 2 more authors.
Transportation Research Record | Year: 2013

NCHRP Project 15-35, Geometric Design of Driveways, was initiated to help address the lack of comprehensive research and national design guidance for the design of driveway connections to roadways. The research initiated with this project included an extensive literature review, a survey of state agencies and contacts with interest groups, and fieldwork to measure traffic attributes. The project produced two publications: a research report on the NCHRP website and NCHRP Report 659: Guide for the Geometric Design of Driveways. This paper considers the following topics: (a) What design issues were identified Current design practices may not adequately consider the range of all driveway users: bicyclists, motorists, and pedestrians. The paper discusses the vulnerability of various users on the basis of historical crash data. (b) What user attributes were found The research produced information about the driveway grades at which the undersides of vehicles may drag and the speeds at which vehicles on urban arterials entered commercial driveways having radii ranging from 13 to 20 ft. (c) What design practices were recommended The guide presents a number of design practices to better meet the needs of all users. This paper provides useful information for design consultants and local government professionals.


Scott A.C.,Elon University | Barlow J.M.,Accessible Design for the Blind | Guth D.A.,Western Michigan University | Bentzen B.L.,Director of research | And 2 more authors.
Journal of Visual Impairment and Blindness | Year: 2011

Five cues were evaluated with respect to their usefulness in directing the headings of pedestrians who were blind during street crossings. The study was conducted at a simulated crosswalk, with the angle of the crosswalk varied relative to the approach and direction of the slope of the ramp. Three cues worked well over the distance equivalent to the width of a six-lane road. © 2011 AFB, All Rights Reserved.


Crandall B.,Smith Kettlewell Rehabilitation Engineering Research Center | Bentzen B.L.,Accessible Design for the Blind | Myers L.,519 Northern Ave.
International Journal of Emergency Management | Year: 2010

Emergency procedures vary according to the type and extent of emergency, size of building, occupancy and type of building construction. There is no agreement on how emergency egress information should be provided for persons who are blind. This research investigated the efficacy of a Braille (Brl) sign, a Raised Print (RP) sign, a Tactile Map (TM), an audible route description activated by a pushbutton and exit signs equipped with Remote Infrared Audible Signage (RIAS) for enabling persons who are blind to travel routes to exits. The efficacy of each format in terms of time to acquire route information and time to travel a route was measured. Blind travellers' perceived needs and desires for obtaining emergency egress information were also investigated. Both RIAS and pushbutton-activated verbal route directions enabled participants to access and use emergency egress information efficiently. Auditory information was preferred above tactile information. Of the tactile formats, Brl resulted in more efficient access to egress information than RP and TMs and was preferred. This research is a first step in addressing the complex issues involved in providing emergency egress information to persons who are blind. Copyright © 2010 Inderscience Enterprises Ltd.


PubMed | Accessible Design for the Blind
Type: Journal Article | Journal: AER journal : research and practice in visual impairment and blindness | Year: 2011

PURPOSE: Although Accessible Pedestrian Signals (APS) are often assumed to provide wayfinding information, the type of APS that has been typically installed in the U.S has not had positive effects on finding crosswalks, locating pushbuttons, or providing directional guidance. This paper reports the results of research on crossings by blind pedestrians at complex signalized intersections, before and after the installation of APS with innovative audible beaconing features, designed to improve wayfinding. METHODS: Objective data on measures of street crossing performance by 56 participants was obtained at four intersections, two each in Charlotte, NC, and Portland, OR. RESULTS: In the first round of testing, APS with beaconing features resulted in only slightly improved wayfinding. Revisions to the audible beaconing features resulted in improved performance on four measures of wayfinding as compared to the pre-installation condition: beginning crossings within the crosswalk, ending crossings within the crosswalk, independence in finding the starting location, and independence in aligning to cross. IMPLICATIONS FOR PRACTICE: Use of APS that provide beaconing from the far-end of the crosswalk show promise of improving wayfinding at street crossings.

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