D11 Environmental Access 6 Ques Flashcards Preview

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Flashcards in D11 Environmental Access 6 Ques Deck (17):
1

Identify potential barriers to accessibility for learners in the home, school, work, and community environments including transportation systems.

We recognize that people without disabilities make mistakes and have accidents, so there are numerous requirements and guidelines for making the environment safer for them. Some of these requirements work for persons who are visually impaired and some do not particularly if they require vision to be effective, such as signs that read Caution, or flashing warning lights. It is also recognized that wayfindfiag (that is, moving purposefully through the environment toward a destination) or orientation in our complexly built environment is facilitated for all persons by information such as numbers on rooms,  elevators, and buildings; street signs at intersections; numbers and destination signs on buses; and directional signage in transit stations and airports. Other travel information that we have come to expect includes maps, building directories, and transit schedules. These kinds of information are an important part of  what makes the environment accessible to all people. Therefore, such warning and wayfinding information also needs to be  made easily accessible to individuals who are visually impaired. Orientation and mobility (O&M) specialists are in  a unique position to assist architects, traffic engineers, planners, and designers in considering the needs of individuals who are blind or visually impaired, and to assist their clients in asking for improvements that make the built environment more accessible to them. In order to do this, O&M specialists need to be aware of the disability  rights, regulations, and standards related to access, as well as possible solutions to common problems experienced by individuals who are blind or visually impaired. Often an access problem can be solved by appropriately bringing it to the attention of the person in charge of a building or facility. 

2

What is meant by Universal Design and how does it assist learners with visual impairments?

Universal design means simply designing all products, buildings and exterior spaces to be usable by all people to the greatest extent possible.

Over time, this emphasis is expected to provide a more usable environment, since an increasing proportion of the population is living longer and consequently developing disabilities. The concept of universal design recognizes that a design that facilitates getting about by persons with disabilities typically benefits most other people as well. For example, signs that can be rea  by persons with low vision are easier for all persons to read.  Curb ramps are helpful  to people with luggage, parents pushing strollers, and delivery personnel, as well as to individuals with disabilities who use wheelchairs or who cannot negotiate steps. In one study persons who were not visually impaired were asked  to rate  the effect on their travel of particular design  characteristics intended to make transit stations and  vehicles more accessible for visually impaired persons. The result was that a majority of persons thought these design characteristics would make their own travel easier. In 2006, the Institute of Transportation Engineers (ITE), an international professional organization of more than  I7,000 individuals working in transportation design and operations, identified "designing for all users" as a major issue for their members. The groups that transportation  professionals must  consider as users of their facilities include bicyclists; pedestrians, including those with  disabilities; and all types of motorized vehicles ranging in size from motorcycles to large trucks and buses. Balancing the  needs of all users in the transportation environment is a challenge that is new to many of the designers and  engineers; the focus has traditionally  been on moving motorized vehicles as efficiently as possible. Course work on designing for pedestrians and bicyclists has been added to transportation engineering programs; however, most practicing engineers still have much to learn about the needs of individuals with disabilities.

3

What is meant by the term “wayfinding”?

Researchers interested in the  effects of environmental design on spatial orientation typically use the term wayfinding to encompass all of the perceptual and cognitive tasks that enable travelers to find their way to destinations. Wayfinding may also be considered to be synonymous with the "orientation" component of orientation and mobility. It has been found, in general, that complex environments cause disorientation for sighted travelers, as do environments with repeated symmetrical designs. Areas lacking distinctive landmarks are also confusing.

4

Define the concept and describe the application to learners with visual impairments

logical layout

Layouts in which users can anticipate locations of facilities-such as stairs located next to elevators or men's and women's restrooms being adiacent to one another-help all users solve orientation problems.

5

Define the concept and describe the application to learners with visual impairments

visibility

Environments in which key features such as handrails, stair nosings (leading edges), and doors have high visual contrast with their surroundings are safer and more negotiable for all sighted persons, including those with  low vision.

6

Define the concept and describe the application to learners with visual impairments

lighting

Good lighting enhances visibility of signs and architectural  features and does not cause glare or heavy shadows. Although optimal lighting for individuals varies, in general, persons with low vision are thought to  need 50-100  percent more light than persons with unimpaired vision. Persons who are 60 years of age also need approximately twice as much light as persons who are 40.

7

List three ingredients of sign legibility

In order for individuals who are blind or visually impaired to benefit from information provided on signs, the signs must first be located, then read, and understood. This is true whether the signs are in conventional print or electronic, and whether they are tactile or audible.

Making signs understandable. For signs to be understood, they must be in plain language that is, the common  language of  users in that geographic area, not the  language ofthe staff or planners. Wording signs in a  way that is understandable may require interviewing people who will use a building or facility.

 

Print signs that have high contrast and are well designed, well placed, clean, and well illuminated, but not unduly affected by glare, can be legible to many people with low vision, especially if readers can get close enough. There is a limited amount of information on design criteria that enhance sign legibility for persons who are visually impaired.  Based on mathematical models of low acuity, a combination of distance and visual angle, and clinical measures of visual acuity, ADA-ABA-AG  lists the character heights that are required for signs that are to be read at particular distances and viewing angles (expressed as height above the floor to the baseline of characters). These requirements are intended to enable persons with as little as 20/200 acuity to be able to read the signs, but this assumes that signs have a very legible font and that they are high in contrast, low in glare, and well illuminated. All of these are factors that affect legibility of signs.

In general, font width, stroke width, and character spacing in the middle of the range provided in ADA-ABA-AC may be most legible. Characters and their background must have a nonglare finish, and characters must contrast with their background, either light on dark or dark on light.

For persons with low vision, critical details of pictograms may not be perceptible. ADA-ABA-AG (703.6) requires that  pictograms be accompanied by print. It can never be assumed that pictograms alone--no matter how large or high in contrast they are--will communicate the same message to all viewers.

CMS, such as flip-dot, light-emitting diode (LED), or liquid crystal display (LCD)  signs, can be particularly difficult for  persons with low vision. Some types of CMS are now very high in resolution, and strokes appear nearly continuous. However, low-resolution CMS-especially  those with curved or diagonal lines-appear somewhat jagged and are still very common, especially in transportation applications. In general, character heights for low-resolution CMS need to be one-third larger than for print signs that are to be read at the same distance.

Tactile signs are composed of braille or large type raised characters, intended to be read by touch. Tactile signs inevitably have a drawback for all readers, however-they cannot be read until touched by the reader; thus, they cannot provide orientation information from a distance. In addition, reading more than a number or name in raised tactile characters is so time-consuming that few touch readers are likely to take the time to attempt to gain orientation information in this way.

Signs are easy to locate when they are in consistent locations. Tactile signs are required, however, only where permanent signs identify rooms or spaces (such as room numbers, restrooms, exits, and special-purpose rooms like an auditorium). The problem of finding signs is much  greater for touch readers than for print readers, which makes standard placement necessary. ADA-ABA-AC require that tactile signs be located between 48 inches and 60 inches above the floor or ground surface and alongside the latch side of doors  (so open doors will not obscure the signs). If there are double doors, the sign should be located to the right of the right-hand  door. 

8

What is the recommended placement of an audible pedestrian signal (APS)?

Installation in the proper location in relation to the crosswalk is most important. Recent research, Draft PROWAG, and the MUTCD in the United States all recommend that each APS device should be on a separate pole, located no more than 10 feet (3m) from the curb line (but closer if possible) and as close as possible to the line of the associated crosswalk that is farthest from the center of the intersection. Two  APS on a corner should be at  least 10 feet  apart, according to Draft PROWAG and MUTCD, in order for pedestrians to easily distinguish which device is sounding.

9

Explain the benefit of APS to a learner with a visual impairment.

The ACB and AER surveys documented a number of street-crossing difficulties experienced by pedestrians with visual impairments that may be partially ameliorated by APS. Many respondents reported difficulty with knowing when to begin crossing because traffic flow was intermittent, the surge was masked by right turning traffic, the intersection  was too noisy, or the surge of traffic was too far away. Many respondents also reported difficulty with crossing straight across the street because traffic was intermittent, the intersection was offset, or because there was no parallel traffic. A number of problems with pushbuttons were documented not knowing whether a button push was needed; finding pushbuttons; telling which crosswalk was actuated by a pushbutton; and returning to the crosswalk from a pushbutton that was located too far away in time  to prepare for crossing. 

Many respondents had some experience with APS and found that the information provided by the APS installed at that time still left them with a number of crossing difficulties. In order of reported  frequency: They could not tell which crosswalk had the Walk signal; the signal was too quiet; they could not  remember which of two sounds was associated with crossing in a particular direction; information was inadequate for guiding them across the  street they were confused by the sound of an APS for another intersection; the signal was too loud; or the signal was confused with a bird call. The most common APS in the United States at the time of these surveys were loudspeakers mounted on top of pedestrian signal heads. These speakers emitted a tone (most commonly a cuckoo or cheep) from both ends of crosswalks during the Walk interval only. They were silent during the rest of the time allotted for pedestrians to complete crossings. Older APS installations are still commonly of this  type. The APS that are now recommended, and becoming more common in the United States, are integrated into the pushbutton and supply the same information that is provided  by the visual pedestrian signal in both audible and vibrotactile formats. All sounds come from the pushbutton and its housing, and they typically include a pushbutton locator tone in addition to an audible Walk indication. The pushbutton locator tone repeats constantly, at one-second intervals, to tell pedestrians that there is a pushbutton and to help them locate and use it. Tactile arrows are also a standard feature to help blind pedestrians determine which street  the device serves. The arrow typically vibrates during the Walk interval to communicate Walk signal information to pedestrians who cannot hear or who want to tactually  confirm audible signal information. Audible beaconing-or providing a signal loud enough to be heard across the street for directional guidance-is provided only on request with this type of APS. A  pedestrian requesrs special features by holding the pushbutton in for more than one  second.

10

Describe the effectiveness of tactile guidestrips when used at street crossings.

Tactile guidestrips have been  demonstrated to be  effective in some  situations. Tactile guidestrips can  be raised about 1/4 inch (7 mm) above the road surface, and are typically installed in the center of crosswalks. The additional line in the crosswalk area can be confusing,  and some advocates instead suggest installing the guidestrip as part of the crosswalk line farthest from the center of the intersection. A guidestrip is used by following it, using constant-contact technique with a long cane. Questions remain about the ability of pedestrians who are blind to follow guide strips when crossing the street, while still maintaining appropriate attention to traffic sounds, and about the maintenance and durability of guidestrips, particularly in areas where snowplows are used. Another strategy that has received limited attention in the United States is to incorporate tactile guidestrips into both edges of crosswalks. Where this is done, pedestrians who are blind do not need to trail a guidestrip across the  crosswalk; they need to  be alert for an indication that they  are about to travel outside the crosswalk. Research is needed to determine which system works best, both from the perspective of the pedestrian who is visually impaired and the jurisdiction installing and maintaining the markings.

11

Describe accessibility issues in transit stations and what modifications can be made to assist the learner with a visual impairment.

Some accessibility issues in transit stations are similar to  issues in buildings, and the discussion of protruding  objects, elevators, signs, and stairs, in the earlier section on Accessibility of Buildings can be applied to the transit station environment. Transit stations also present some challenges to safety and orientation and access to information for persons with visual impairments that are not present in other buildings or at intersections, such as platform edges and gaps between cars, orientation within the station, locating bus stops, and locating vehicle doors. 

One element common to most light, heavy, rapid, or monorail transit stations is a waiting platform that is  raised above the track bed and therefore has a drop-off. In other environments, pedestrian walkways are commonly required to have guardrails or barriers along edges  where there is a drop-off. However, in rapid rail systems in the United States, there is typically an unprotected drop-off  and the track bed includes an electrified third rail. All persons on these transit platforms are at risk of falling, as well as for vehicular and sometimes electrical accidents. The frequently severe consequences of falls onto track beds have resulted in a variety of measures to reduce risks for all transit riders. These include guardrails, safety yellow warning stripes, between-car barriers, detectable warning surfaces, and lights along platform edges. Travel techniques are often modified for travel along platforms with a drop-off and even minor deviations from perfect  cane technique can result in failure to detect the edge with the cane. In some transit  systems, all riders are prevented from inadvertently stepping off platform edges by the presence of barrier walls with doors that open only when  and where vehicle doors open. Guardrails are  used at  a distance from the drop-off in some stations in Japan, especially those used for high-speed trains. Chains or other barriers are attached between cars to prevent passengers from mistaking the space between cars for a doorway. These barriers are required by ADAAG;  however, maintenance of barrier systems and the consistency  of their installation and use has been  problematic in the United States, resulting in some falls between cars by travelers who are blind or visually impaired. In the United  States, ADAAG requires that the detectable warning surface be placed 24 inches deep on the edge of all newly constructed or altered transit platforms, and in key stations of a system ("key stations" meet particular requirements of ADAAG, and usually are major transfer points). As stations  are altered or  reconstructed, detectable warnings will eventually be installed in all stations.

For persons who are blind or visually impaired, the task of locating an unfamiliar bus stop and confirming that it is the correct stop, without very explicit directions or a map, is difficult in locations where bus stops may or may not be marked by shelters or distinctive poles, and  where they may be located anywhere along a block. Other aids to the location of bus stops are tactile signs, RIAS and remotely activated audible signs, the use of distinctively shaped poles, and attaching signs with raised characters at standard heights on bus stop poles. Standard stop location and distinctive stop features such as shelters, special poles, and special pavers are the most common solutions to this problem. Charlotte, North Carolina, has developed a unique schedule information sign that is installed on each  bus stop to make it easier to distinguish a bus stop from a signpost for another type of sign. Crandall, Bentzen, and  Myers (1995) found that when research participants using dog guides had only tactile signs to identify bus stops,  they resorted to leashing their dogs as they haptically  explored to find poles or shelters that might be bus stops because the dogs guided them away from poles and shelters. The Talking Signs system and tactile (raised character and braille) signs were used in a pilot project to label several bus stops in San Francisco. Travelers who are blind were more successful at locating unfamiliar bus stops by using RIAS alone than by using only tactile signs. While participants generally preferred RIAS to tactile signs, most liked the idea of having tactile signs because they were absolutely definitive, and using them did not require that the user carry any technological devices. The use of personal navigation technology could make independent location of unfamiliar bus stops possible for users if it is sufficiently precise and uses databases containing bus  stop locations. Bus stop location information is available for the cities of Charlotte, North Carolina, and Portland, Oregon, on some accessible GPS devices as this book is published, and more cities are making such information available. GPS information provides general location information and route numbers for buses stopping at a particular  location. Users must be aware that GPS locations are not precise, so two stops that are close together could be confused. Confirming information such as tactile or audible signs on the pole or shelter can be helpful, even when transit  stop information is provided by a GPS system.

12

Describe the technology involved in purchasing a ticket in a modern transit system and the challenges for the learner with a visual impairment.

Paying one's fare in a modern transit system frequently requires interaction with one or more kinds of ticket  purchase machines or ticket validating or canceling machines. Many technologies exist; ticket purchase equipment typically requires the user to follow a particular sequence to insert money, locate and press a number of buttons, and remove a ticket. In order to know the value of  a ticket, users may be required to read electronic messages. Turnstiles typically require that tickets be inserted in a particular direction. In some locations, in order to purchase a ticket with the correct value for a specific trip, riders must locate their origin and destination on a  map to determine the number of fare zones between them, or they must refer to a table of fares for different destinations. ADAAG recognized that such fare equipment  presents obstacles to independent use by persons who are visually impaired and required equipment to be independently usable by travelers who are blind. ADA-ABA-AG requires machines to be speech-enabled and to provide operating instructions, transaction prompts, user input verifications, error messages, and all displayed information. Braille instructions for initiating the speech functions are required. The guidelines do allow use of either a standard handset or headphone jack (requiring individuals who are blind to have earphones with them to use the equipment). Tactilely discernable input control is  required; however, number keypads can be arranged either in ascending (computer  keys) or descending (telephone keypad) order. Some items are not speech-enabled for privacy  easons, such as customer account numbers. Tactile labels may be very helpful to touch readers who are familiar with operation of the equipment.  Ticket kiosks have been made accessible in pilot  projects through addition of speech technology and software and hardware adaptation, such as those described earlier in the section on Information Kiosks. Simply orienting fare cards correctly can be time consuming for travelers who are visually impaired, making their travel inefficient and delaying other passengers. A simple tactile indicator on  one corner of a fare card, such as a cutoff corner or a notch, can greatly increase the efficiency of fare card orientation for all users. In transit systems where tokens are used for payment, it may be difficult to distinguish tokens from coins using touch alone. In the United States, a token with a hole in it is readily distinguished from coins. This speeds fare payment for all  riders who reach into pockets or purses to find tokens. These features are  recommended in ADA-ABA-AG in Advisory 707. Another  approach is the use of "smart cards," which would indicate to fare machines that temporary modifications in machine function are desired by a user. Such modifications might include speech output, large print, and a slower operating rate. A smart card is a credit card size plastic card incorporating an integrated microcircuit. There are a number of types of smart  ards in use in various parts of the world; the most common is a prepaid card that may be used for a variety of applications, including transit fares and telephone calls. Contactless smart cards are being  developed that allow functions to be performed without direct contact between the card and the terminal. Use of contactless cards in transit can speed  movement of all passengers through fare barriers. Contactless smart cards could also activate an audible signal to guide users to a fare transaction machine. Smart cards are being used and  considered for improving access to many services for all users. For persons with visual impairments, the advantages are that no card reader or slot needs to be located, and the  card does not have to be taken out of a purse or wallet  and correctly oriented and inserted.

13

Explain how an O&M specialist could achieve an environmental modification that  addresses barriers to accessibility.

While some O&M specialists are reluctant to get involved in  advocacy, there is a great need for more education in the building community (architects, transportation engineers, and planners) to encourage built environments that enable efficient and safe travel by individuals with visual impairment. O&M specialists are important consultants, together with local persons who have visual impairments, in providing education about features that help make travel safer, and independent orientation possible, for individuals who are blind or who have low vision. It is particularly important for O&M specialists and blind travelers to be involved in the development and implementation of specialized wayfinding systems for visually impaired persons because appropriate technology and the  placement and wording of signs requires a high level of sophistication regarding the orientation strategies and capabilities of persons with low vision. O&M specialists need to be active, together with persons with visual impairments, in setting standards and monitoring environments to be sure that they comply. In the United States, there is an extensive process that allows public input  and comments on ADA standards, the Manual on Uniform Traffic Control Devices, and other federal regulations, guidelines, and standards. In most locations, there is a Metropolitan Planning Organization (MPO) or Rural Planning Organization (RPO) that is required to develop a Transportation Improvement Plan (TIP) for their jurisdiction on a regular basis. These plans often include road-widening projects, installation of sidewalks, signal  systems, trails, and other transportation features; they are usually developed three to five years in advance. The TIPs are submitted to the Federal Highway Administration in order to qualify for federal funding. In development of the TIP, there are specific public input opportunities. It is important for individuals who are blind or visually impaired, O&M specialists, and organizations providing services to individuals who are blind to  show up at these public  hearings and present concerns regarding accessibility to  sidewalks, street crossings, and transit services. 

In making requests for modifications in building or intersection design, O&M specialists and their students need to work together as much as possible. The person with  a disability is allowed to file a complaint of discrimination under civil rights laws; the O&M specialist  does not have that status. Before making a request, it is helpful to research current information about possible modifications and to understand some of the applicable regulations. Consumer groups or professional organizations may have formal environmental access committees that can assist in locating updated information and government agencies such as the Access Board in the United States, which provides technical assistance on current regulations. It may also be important for the O&M specialist to direct his or her request to the appropriate official. Often, different agencies control different aspects of the roadway, sidewalk, and building environment. Finding the person who controls the relevant location or intersection may require informational phone calls to the number listed in the phone book under city, county, and  state government offices for traffic engineering/public works and the state department of transportation, and asking who you need to contact about the traffic signals at that intersection. It can also be helpful to ask about local policies  (for example, the policy and procedure for installing accessible pedestrian signals). The actual  request for modifications is usually strongest if it comes from a  pedestrian who will personally benefit from the modification (for example, a person who is blind, has low vision, is disabled, or is  a senior). The individual needs  to make the request in writing so that there is documentation of the request having been made to the official who  has been identified as being responsible for the intersection or building. The letter needs to include wording that addresses the civil rights issues of "access to information." The ADA and the requirements to make facilities accessi ble can be  referred to later. A supporting letter can be sent by the O&M specialist on professional letterhead, restating the reasons for the request for modifications. A follow-up phone call from the O&M specialist with an offer to look at  the facility together with a responsible official is often helpful. In that visit, it may be appropriate to demonstrate the typical travel techniques or provide an experience with  occluders or low-vision simulators to help the designer  understand the issues. Designers and planners often are totally unfamiliar with modifications that can be helpful and need assistance in locating resources and planning appropriate solutions. If there is no response to a letter or call, it  maybe necessary to involve an agency-designated ADA official and the elected official (city council member, county supervisor, state assembly member, or state senator, depending on the jurisdiction) for the area. If the designer, planner, or engineer refuses to consider the  appropriate modifications, a response in writing needs to be requested. If  the request falls under ADA or DDA (in the United Kingdom or Australia) regulations, documentation of the response is usually needed before filing a complaint. ADA and DDA regulations include a process for filing discrimination complaints.

14

Describe redesign modifications which could be made to assist a learner with a visual  impairment for the following environmental challenges:

protruding objects

Objects that protrude into travel paths can endanger persons who have visual impairments; U.S. guidelines therefore limit the amount by which objects can protrude from a wall or from a signpost. Below 27 inches and above 80 inches, objects or signs may extend any distance into the hallway or sidewalk, as long as minimum passage width  requirements are met. However, obstacles that have  leading (lower) edges more than 27 inches above the floor or ground and lower than 80 inches above the floor or ground are not allowed to protrude into the travel path more than 4 inches. These specifications attempt to provide for facilities such as drinking fountains and  telephones that are both accessible to persons who use wheelchairs and are likely to be detected by travelers who are blind and use long canes. A proficient adult long cane user is  expected to encounter the obstacle with the shaft of the cane in time to avoid bodily contact.  However, a pilot project found that proficient adult blind  travelers using long canes had frequent bodily contact with wall-mounted objects protruding 4 inches at heights of 27-70 inches, and  even more frequent bodily contact with pole-mounted objects protruding 12 inches. While no research  is available on this issue, the smaller stature of children makes it more difficult to encounter the protrusion with a cane in time to avoid bodily contact, when the lower edge is at 27 inches. In new construction, it is better to recess wall-mounted objects such as drinking fountains and fire extinguishers. ADA guidelines for post-mounted signs and objects are not consistent. ADA-ABA-AG  allows signs to protrude 12 inches from posts, while Draft PROWAG limits  post-mounted objects to 4 inches maximum protrusion.

Most O&M specialists would agree that in all  environments, it is desirable that pole-mounted objects  protrude no more than 4 inches. Where there is no alternative to mounting a large sign on a pole, the sign should be mounted on two poles placed at both sides of the sign, and a crossbar should connect the two poles at a height of about 12 inches. The crossbar will readily be detected by a traveler using a long cane.

A protruding object or structure that can be particularly hazardous is the underside of a staircase or escalator that  is not enclosed. Travelers who are blind or visually impaired may run headfirst into such structures without previously encountering any part of the structure with the long cane. Such construction is prohibited by ADA-ABA-AG 307, which requires a guardrail or barrier where vertical  clearance is less than 80 inches. At existing unprotected stairs or escalators, a rail can be added, or benches, planters, or other furnishings can be used. These are all relatively inexpensive solutions.

15

Describe redesign modifications which could be made to assist a learner with a visual  impairment for the following environmental challenges:

stairs

Stairs are an especially common cause of accidents for everyone; hence, considerable attention has been paid to making them safe and easy to negotiate. Some of the specifications for stairs and handrails are also helpful to  many travelers who are blind. In general, stairs are  considered to be safest and easiest to negotiate when:  treads and risers are at a moderate width and height and the dimensions are the same for the full width of each stair  and for the entire length of a  staircase; when stair nosings protrude slightly beyond the base of the riser below; when  risers are closed; when handrails are continuous  on both the inside and outside of a staircase; and when the ends of handrails protrude horizontally about 1  foot beyond the top and bottom of the stairs. The ends of handrails must be rounded and returned to the wall, floor, or a post in such a  way that they do not become protruding objects. Smaller stairs are not recommended in children's facilities, although an extra lower handrail may be provided. For persons with low vision, it is often difficult to see where stairs begin and end. Patterned carpeting on stairs can provide a "camouflage" effect resulting in stair edges that are not  easily seen and can be misjudged. Adequate lighting  at stairs is also important for visual recognition of  stair locations. It is extremely helpful if  the nosings (the front  edge) of stairs contrast visually with the treads and risers.  It is also helpful if stringers (the sloping board beside the  treads on each side of stairs) contrast visually with  adjoining treads and risers. Draft PROWAG specifies a minimum 2-inch strip at the front of each tread that contrasts visually with the tread and riser. This type of strip  can easily be added with paint to most surfaces. In some countries, detectable warnings (also called tactile ground  surface indicators  or TGSIs) are required at the top and bottom of staircases.

16

Describe redesign modifications which could be made to assist a learner with a visual  impairment for the following environmental challenges:

platforms at rail stations

One element common to most light, heavy, rapid, or monorail transit stations is a waiting platform that is  raised above the track bed and therefore has a drop-off. In other environments, pedestrian walkways are commonly required to have guardrails or barriers along edges  where there is a drop-off. However, in rapid rail systems in the United States, there is typically an unprotected drop-off  and the track bed includes an electrified third rail. All persons on these transit platforms are at risk of falling, as well as for vehicular and sometimes electrical accidents. The frequently severe consequences of falls onto track beds have resulted in a variety of measures to reduce risks for all transit riders. These include guardrails, safety yellow warning stripes, between-car barriers, detectable warning surfaces, and lights along platform edges. Travel techniques are often modified for travel along platforms with a drop-off and even minor deviations from perfect  cane technique can result in failure to detect the edge with the cane. In some transit  systems, all riders are prevented from inadvertently stepping off platform edges by the presence of barrier walls with doors that open only when  and where vehicle doors open. Guardrails are  used at  a distance from the drop-off in some stations in Japan, especially those used for high-speed trains. Chains or other barriers are attached between cars to prevent passengers from mistaking the space between cars for a doorway. These barriers are required by ADAAG;  however, maintenance of barrier systems and the consistency  of their installation and use has been  problematic in the United States, resulting in some falls between cars by travelers who are blind or visually impaired. In the United  States, ADAAG requires that the detectable warning surface be placed 24 inches deep on the edge of all newly constructed or altered transit platforms, and in key stations of a system ("key stations" meet particular requirements of ADAAG, and usually are major transfer points). As stations  are altered or  reconstructed, detectable warnings will eventually be installed in all stations.

17

Describe redesign modifications which could be made to assist a learner with a visual  impairment for the following environmental challenges:

blended curbs

The presence of a drop-off in the line of travel, which could be tactilely and kinesthetically identified as a curb, used to be the only information needed to tell travelers in urban  and suburban areas that they had arrived at intersecting streets. Since the 1960s, however, increasing attention to  sidewalk accessibility for persons who cannot negotiate curbs has resulted in the elimination of drop-offs at many intersections. Curbs have been replaced by clearly defined curb ramps at some intersections and at others by  blended transitions, depressed corners, or raised intersections (designs in which the sidewalk is basically level with the street). 

In the 1960s, Japan was the first country to accommodate for the information lost by the removal of curbs; they placed a warning surface at the bottom of curb ramps that was detectable both underfoot and by a person using a long cane. Although there was no standard, most of the Japanese surfaces that were intended to be warnings had a surface configuration of domes, somewhat flattened or truncated on top, which were about  2.5 inches apart (measured from center to center). Most warning surfaces were placed on the lower end of curb ramps or along the former curb line where there were blended curbs. Warning  depths in the direction of travel varied from about 12 inches to about 36 inches. Materials used included rubber,  stainless steel, cast pavers (small blocks specially  designed and treated for use in walkways, similar to bricks),  and tiles. Japanese warning surfaces are now tightly  specified based on research. They are part of a wayfinding system that includes the use of directional guidance tiles. The truncated dome surface is used as an "attention field" at intersections of paths that are demarcated  by directional tiles, as well as at intersections with streets. It is also used to designate such landmarks and destinations as elevators, tactile maps, ticket machines, and information kiosks. Guidance tiles, with a linear surface pattern  intended to provide directional information, are also quite common in Japan. In England, a warning surface with a standardized pattern of truncated domes (referred to there as "blister paving") has been recommended for use in  specified locations and dimensions on curb ramps and blended transitions since 1983. These warnings can now be found throughout England. In addition, several other  surface configurations have been identified and are installed as guidance and information tiles. In the United States, the 1980 ANSI standard required tactile warnings for the entire surface of curb ramps, and a 36-inch-wide strip was specified along the entire edge of what were referred to as "hazardous vehicular ways". The standard loosely described a number of surfaces that could be used instead of the truncated dome surface used in other countries. Some research preceded this standard, which indicated that a ridged rubber mat was highly detectable. Nevertheless, the ridged rubber mat was not included in the standard, but grooved concrete was, although no testing had indicated that grooved concrete was detectable. In 1991, ADAAG  4.29 required and provided specifications for a detectable warning that was similar to the truncated domes used in Japan, England, and  Australia. The U.S. surface specification was based on the above studies and additional research sponsored by the U.S. Department of Transportation. The truncated  dome surface specified in ADAAG, and others much like it, have been repeatedly demonstrated to be highly detectable when used in association with a wide variety of adjoining surfaces. Many other surfaces that were anticipated to be highly detectable have not proved to be reliably detected underfoot and under cane. ADAAG (Access Board, 1991) required detectable warnings on the entire  surface of  curb ramps; 3 feet-wide in the direction of travel at blended transitions and along the edge of reflecting pools, water  features, or fountains in the pedestrian area; and 2 feet-wide along the edge of transit platforms. This quickly became one of the most controversial provisions of ADAAG, resulting in the suspension of the requirement from 1994 until 2001. Detectable warnings on curb ramps  were advocated for by the American Council of the Blind  and the O&M  profession, and opposed by the National Federation of the Blind and by some organizations  concerned with safety and negotiability for persons with mobility impairments. 

Blind  persons who opposed detectable warnings at intersections claimed they were unnecessary and that no research demonstrated that travelers who were blind needed additional cues to detect  streets reliably at curb ramps or blended curbs. Two subsequent research projects confirmed that the removal of the curb ramps resulted in the inability of even skilled, frequent travelers who were blind to detect some streets. Bentzen and Barlow (1995) found that on 35 percent of approaches to unfamiliar streets on curb ramps, blind travelers who used long canes failed to detect the presence of an intersecting street before stepping into it; this was true even when there was traffic on the intersecting street. Some of the curb ramps used in the study had steeper slopes than allowed by ADAAG. On curb ramps that met the ADA requirements or had lower slopes, blind travelers stepped into the street on 48 percent of the approaches. Both projects found that street detection was more likely when curb  ramps were at the apex of the corner (also called diagonal curb ramps) than when they were in the line of travel. However, other studies found that apex curb ramps were more likely to lead to unsuccessful street crossings. Studies also found that truncated dome detectable warnings on slopes or curb ramps had little negative effect on safety and negotiability for  persons with physical  disabilities in comparison with concrete curb ramps. A majority of persons with physical disabilities generally considered curb ramps with detectable warnings to be safer, more slip resistant, and more stable, and to require less effort to negotiate than concrete curb ramps. However, 25  percent of participants with mobility disabilities preferred curb ramps with brushed concrete surfaces. At a meeting of stakeholders convened by the Access Board in 1995, participants recommended reducing the requirements for detectable warnings at curb ramps so they covered just the bottom 2 feet of the  ramp. Draft PROWAG modified the specifications for detectable warning location to require 24 inches at the base of the ramp for its entire width. That amount had previously been demonstrated to be sufficient to enable detection and stopping on most approaches. It is the same as the distance required on transit platforms, and provided  a clearer information point for blind pedestrians than the previous requirement that resulted in detectable warnings beginning at varying distances from the street, depending on the curb ramp design. 

Technical specifications were also modified in ADA-ABA-AG and Draft PROWAG (R304), permitting a range of dome spacing and specifying the alignment of the domes in a square grid in relation to the gutter or change of slope at  the base of the ramp. At this time, the truncated  dome detectable warning surface is used fairly consistently in many countries as a warning texture, although placement varies. In general, the detectable warning surface is not  used to provide alignment information, nor does it indicate  a "safe" crossing Iocation, but it provides a cue that  pedestrians should stop and evaluate their position and potential  hazards before proceeding further. Individuals who are blind or who have low vision should be aware of the purpose and meaning of detectable warnings.