A pilot study of pedestrians with visual impairments detecting traffic gaps and surges containing hybrid vehicles

Abstract

The increasing number of hybrid and quiet internal combustion engine vehicles may impact the travel abilities of pedestrians who are blind. Pedestrians who rely on auditory cues for structuring their travel may face challenges in making crossing decisions in the presence of quiet vehicles. This article describes results of initial studies looking at the crossing decisions of pedestrians who are blind at an uncontrolled crossing (no traffic control) and a light controlled intersection. The presence of hybrid vehicles was a factor in each situation. At the uncontrolled crossing, Toyota hybrids were most difficult to detect but crossing decisions were made more often in small gaps ended by a Honda hybrid. These effects were seen only at speed under 20 mph. At the light controlled intersection, parallel surges of traffic were most difficult to detect when made up only of a Ford Escape hybrid. Results suggest that more controlled studies of vehicle characteristics impacting crossing decisions of pedestrians who are blind are warranted. Keywordsblind; hybrid; visually impaired; pedestrian; crossing; gap IntroductionIn 2004, National Health Interview Survey (NHIS) data revealed prevalence rates of visual impairment of 8.8% or 19.1 million (Lethbridge-Cejku, Rose & Vickerie, 2006). The Eye Diseases Prevalence Research Group (2004) estimates a 70% increase in [legal] blindness as well as in low vision by 2020. Given such numbers, it is fair to assume that a significant portion of this population is accessing public sidewalks and thoroughfares as pedestrians. In doing so, there is a certain probability that a pedestrian with a visual impairment will come into conflict with an automobile. This probability increases as pedestrians with visual impairments encounter increasingly complex traffic situations (e.g., roundabouts) or have limited access to important orientation information (e.g., the sound of an approaching vehicle) (Ashmead, Guth, Wall, Long & Ponchillia, 2005;Barlow, Bentzen & Bond, 2005).Corresponding author: Dr. Robert Wall Emerson, robert.wall@wmich.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author Manuscript NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptThere is a fear that increasingly quiet vehicles on the road will increase pedestrian-vehicle conflicts in the near future (e.g., TheGreenCarWebsite.co.uk, September, 2008) prompting calls for research and legislative action (Wunder, 2008).Epidemiological research on pedestrian safety during the past decade (Campbell, Zegeer, Huang & Cynecki, 2004; Natio...

Accessibility of urban spaces for visually impaired pedestrians

“…These different stances regarding the priority of the pedestrian will clearly have their influence on the review that follows concerning walkways and pedestrian routes (including obstructions); pavements, kerbs and tactile paving; street crossing and intersections, obstructions; and access to public transit. Two general areas for future concern are first that the DfT local transport note (DfT, 2011) does not appear to address the implications around the uptake of hybrid electric vehicles, which are less easy to detect by blind pedestrians (Wall Emerson et al, 2011). Second, it does not address factors relating to the degree of unfamiliarity of space, which are issues for tourists/visitors who are blind and partially sighted.…”

“…In this respect, depending on any mobility aids used, the cognitive load is higher owing to the sequential nature of the access. For example, an auditory stream of traffic sounds and intermittent gaps is one source of information for blind pedestrians, potentially aiding alignment to the road when walking alongside it or before considering crossing it (Wall Emerson et al, 2011). In places without designated crossings, it is the sequential detection of auditory cues (e.g.…”

Auditory Perception of Motor Vehicle Travel Paths

“…Wall Emerson, Naghshineh, Hapeman, and Wiener (2011) studied pedestrian road-crossing decisions using gasoline vehicles from ambient traffic and hybrid vehicles operated by the investigators. Pass-by sound was only 2 to 3 dB-A lower for hybrid than for gasoline vehicles at 15 to 30 km/h and equivalent at higher speeds.…”

“…Wall Emerson et al (2011) studied roadcrossing decisions at an unsignalized intersection with hybrid and gasoline vehicles. Ratings of riskiness did not break down neatly between vehicle types.…”

Impact of adding artificially generated alert sound to hybrid electric vehicles on their detectability by pedestrians who are blind

“…In a study conducted in the downtown area of a college town (Kalamazoo, Michigan), surges (starting up from a stationary position) of HEVs were missed at a higher percentage (7.4%–45.7%) than those of ICE vehicles (2.2%) [27]. Furthermore, the National Highway Traffic Safety Administration, using the pedestrian crash data from 12 states, documented that the accident rate of HEVs was twice as high as that of the ICE vehicles in low-speed maneuver conditions, including slowing, stopping, backing up, and entering a parking space [28].…”