WO2001057341A1

WO2001057341A1 - Detectable warning and wayfinding system for persons with disabilities

Info

Publication number: WO2001057341A1
Application number: PCT/US2001/003964
Authority: WO
Inventors: Robert V. Buck
Original assignee: Buck Robert V
Priority date: 2000-02-07
Filing date: 2001-02-07
Publication date: 2001-08-09
Also published as: AU2001236743A1

Abstract

A detectable warning system for persons with disabilities. The system is in one embodiment composed of a surface covering (103) and rectangular block shapes (104). The warning system may utilize a surface texture (107) such as silicon carbide or granite to create a slip-resistant surface with compliant color contrast over the rectangular block shapes (104). This surface texture (107) can be used in or along a hazardous area on the paving or floor surface and helps a person with a physical and/or visual disability distinguish a hazardous area from a non-hazardous area. In additional embodiments, ridges (112) or elongated truncated domes (116) are used to give greater detectability in various locations.

Description

Title: DETECTABLE WARNING AND WAYFINDING SYSTEM FOR

PERSONS WITH DISABILITIES

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

Applicant's invention relates to a detectable warning and wayfinding system for persons with disabilities. This warning and wayfinding system is to be applied to paving and floor surfaces to provide a tactile system whereby someone, for example with a visual disability, would be able to distinguish when he or she is about to enter into a dangerous area, such as a curb ramp, vehicular crossing, stairs, or the like. Also, an embodiment of this invention will provide a comprehensive wayfinding system for people with visual impairments, such as to find their way from one place to another as between stairs and the platform edge in a transit station, to stay within the boundaries of a marked street crossing, find door openings on train and transit platforms, recognize different types of features in the environment, and have directional clues where there are no grass lines, curb hedges, fences or walks. In addition, this invention will provide a visual system to accommodate people that have limited mobility, for example persons in wheelchairs and those who use walkers and walking canes.

2. BACKGROUND INFORMATION

The development of sidewalks and streets, with their identifying curbs-the network of vehicular and pedestrian circulation-gave pedestrians who were blind predictable environmental features that could be used to maintain orientation and safety when traveling independently.

Detection techniques depend on the travel aids used by people who are blind, such as long canes or dog guides, and their amount of vision. First, people who are blind and use a long cane for a travel aid to detect a curb, or any other drop-off such as stairs or a platform edge, by a change in the angle of the wrist and the failure of the cane to contact the sidewalk at the expected level. They must normally come to a stop after taking no more than one step following the cane information. In addition, people who use dog guides are alerted to the presence of a curb or other drop-off such as a platform edge when their dogs stop. They then confirm the presence of the drop-off with a foot. Furthermore, people who have low vision, and do not use either a long cane or dog guide, rely on differences in color or shading of the walking surface. The sidewalk and street may have visual contrast, or the curb material may contrast with the sidewalk or street. With platforms, people who have low vision, and do not use either a long cane or dog guide, rely on differences in color or shading between the platform and the track bed. Usually the platform is a lighter color than the track bed, although the reverse may also be true. Sometimes people having low vision are able to see a colored safety line defining the end of the safe waiting area, and sometimes illumination patterns may be helpful in determining the location of the platform edge.

There are a number of other sources of information about the location of the curb indicating the end of the sidewalk (and the beginning of the street) which may be used by any person having a visual impairment, regardless of their travel aid or amount of low vision. These include traffic sounds, the slope of the sidewalk, the end of a building line, and changes in sun or wind. These are all simply clues to the sidewalk/street boundary. None is a definite cue.

Accessability requirements that were developed in the 1960's resulted in the disappearance of curbs at many intersections. Curb-ramps, blended curbs, and depressed corners became common features. In the absence of a definitive cue-the curbed sidewalk-at the sidewalk/street boundary, it has become much more difficult for pedestrians who are blind to detect streets. When blind pedestrians do not detect a curb at the end of a block, they must rely on multiple clues which, taken together, indicate the high probability that they have come to a street. They may detect a change in slope, which could be a curb ramp, a change in terrain, or a broken sidewalk. The end of a building line or grass line may suggest that there is a street directly ahead. Changes in sun and wind are also clues. However, none of these clues, by itself, confirms the presence of an intersecting street or the direction and boundaries of a street's marked crossing. One of the most reliable clues, when it is present, is the sound of traffic on the intersecting street. But in many locations, and at different times of the day or days of the week, there may be little or no traffic.

Complex traffic operations, including actuated signals and right turn on red, have made it increasingly difficult to analyze the environment using vehicular sound. Large traffic volume and high ambient sound often mask traffic flow and the sounds of vehicles starting and stopping.

Blind pedestrians have become increasingly at risk in urban environments where traffic flow information is complex, unclear, masked by other sounds, or absent. The trend toward aggressive driving has decreased the likelihood that drivers will stop for pedestrians in crosswalks at unsignalized intersections, and the general decline in pedestrian traffic has made it increasingly difficult for blind travelers to obtain assistance for street crossing where needed.

With platforms, there are a number of other sources of information about the general location of the platform edge, such as other riders waiting a safe distance from the drop-off, and changes in air currents. However, falling and fear of falling at high- level transit platform edges have been found to be a major problem and cause of anxiety in blind transit riders. In Bay Area Rapid Transit (BART) in San Francisco, during the ten years before the installation of detectable warnings along platform edges, approximately one-fourth of all accidents along the edges of raised platforms involved persons who were visually impaired. An extensive program of research in the United States to identify walking surfaces that could be used to alert people with visual impairments to the presence of hazards such as streets and platform edges began in 1980.

This research has been conducted by a number of researchers and sponsored by the Federal Highway Administration; the Urban Mass Transportation Administration (now known as the Federal Transit Administration); the Federal Transit Administration; and the U.S. Architectural and Transportation Barriers Compliance Board (Access

Board).

Many tested surfaces have been found to be non-detectable or minimally detectable; these are not appropriately considered to be detectable warnings. It is essential that warnings and wayfinding devices be highly detectable and distinguishable from each other under foot as well as by use of the long cane. A minority of people who are legally blind regularly use a long cane for obtaining surface information as they travel . Other people who are visually impaired use dog guides or their low vision. To detect changes in walking surfaces, they rely on visual contrast and/or under foot information. Low vision is quite variable; a person who often can see street, platform edges and stairs may sometimes be unable to see them because of glare, poor illumination, poor visual contrast, or fatigue.

Early implementations of the ANSI Al 17.1-1980 and ANSI Al 17.1-1986 standard for tactile warnings include a number of surface treatments such as grooved concrete, which were subsequently found not to be highly detectable to pedestrians who are blind. However, grooved concrete is still used in some jurisdictions today, including the states of California and Texas.

In 1991 , the Architectural and Transportation Barriers Compliance Board (Access Board) published the Americans with Disabilities Act Accessibility Guidelines (ADAAG), which included scoping and technical specifications for round-based raised truncated dome detectable warnings at curb-ramps, hazardous vehicular ways, reflecting pools, and edges of transit platforms having drop-offs. The specifications were based on the extensive program of research described above.

Both specifications and scoping for detectable warnings quickly became one of the most controversial issues in ADAAG. Truncated dome detectable warnings were strongly advocated by some individuals and organizations of blind travelers and the orientation and mobility profession. They were strongly opposed by other individuals and organizations of blind travelers and by some individuals and organizations representing people concerned with safety of persons with mobility impairments. Blind persons opposing detectable warnings at intersections and hazardous vehicular ways claimed that other cues were available and that detectable warnings were an unnecessary and costly feature.

In response to business and user concerns about the use of truncated detectable warnings and possibly of trips and falls for signed pedestrians, particularly women wearing high heals, as well as difficulty for wheelchair users in traversing ramps with additional "bumps", since April 1994, ADAAG requirements for truncated dome detectable warnings at curb ramps, hazardous vehicular ways, and reflecting pools have been suspended while the U.S. Access Board has sought additional research as to whether detectable warnings help people with visual impairments, and whether detectable warnings have adverse impacts on people with mobility impairments. The requirement for detectable warning surfaces at transit platform edges remains in effect. Orientation and Mobility Specialists have observed that when visually impaired pedestrians approach streets at curb ramps (or at islands in streets) they are at risk of walking unaware into the path of moving traffic, since there is no clearly defined distinction at curb ramps between the roadway and sidewalk. Research has now been conducted which confirms that for persons who are visually impaired there is a high level of risk of inadvertent street entry associated with the presence of curb ramps, particularly those having slopes of 1 :12 or less (Bentzen, B. & Balow, J., 1995; Hauger, S. Rigby, J., Safewright, M. and McAuley, W., 1996).

By 1998, based on recommendations of the ADAAG Review Advisory Committee which had recently been submitted to the Access Board for the revision of ADAAG, specifications for round-based diagonally spaced truncated dome detectable warnings at platform edges were included in the ANSI Al 17.1-1998 standard on accessibility. In this edition of ANSI A117.1, the texture and visual contrast specifications were the same as those in ADAAG. Alternatively, equivalent detectability could be provided by other means (ACC/ANSI Al 17.1-1998 705.3.2 and 705.3.3). Recent research sponsored by the Ministry of international Trade and Industry of the Japanese National Institute for Technology and Evaluation has systematically varied the height, diameter, and spacing of raised trapezoidal dot ground or floor surfaces intended to be warnings for persons who are visually impaired. The goal of this ongoing research is to determine appropriate specifications for warning (raised dots which are trapezoidal in cross section) and guidance (raised bar) surfaces. No comparable research on the effect of height, diameter and spacing of detectable warnings has been conducted in the United States. This Japanese research also used many more subjects (12) than any research on detectable warnings in the United States. This research confirms the height of 5mm (0.2 in) as being necessary for reliable detection. This research supports the size and spacing of the surface of a detectable warning or wayfinder device where it touches the sole of the shoe affects detectability. Further, tests confirmed a raised trapezoidal warning surface having a 0.9 inch wide base, 0.4 inch wide top, and spaced at 2.35 inches has detectable rates over 90%.

Presently, there are laws that exist to regulate access ways for persons with disabilities. The Texas Accessibility Standards (TAS) were adopted by the Texas Architectural Barriers Act which states that all new construction, alterations, and additions that are constructed after April 1 , 1994 shall comply with the TAS. The Texas Department of Licensing and Regulation administers the Texas Architectural Barriers Act and enforces the TAS.

The format of the TAS is based on the Americans with Disabilities Act Accessibility Guidelines (ADAAG). When the Americans with Disabilities Act was passed, Congress stipulated that state building codes, state standards, city standards, and other model code standards could be certified to be comparable to or more stringent than the ADAAG. Texas was the second state in the United States to obtain certification that the TAS met or exceeded the requirements of the ADAAG. The TAS in some instances exceeds the requirements of the ADAAG.

Under Section 4.7.4 of the TAS and ADAAG, surfaces of curb ramps shall comply with Section 4.5 which states that all walking surfaces along accessible routes must be stable, firm, and slip resistant. Appendix to Section 4.5 in ADAAG provides that people who have difficulty walking or maintaining balance or who use crutches, canes, or walkers, and those with restricted gaits are particularly sensitive to slipping and tripping hazards. For such people, a stable and regular surface, which is slip resistant whether dry or wet, is necessary for safe walking, particularly on stairs and ramps. Wheelchairs can be propelled most easily on surfaces that are hard, stable, and regular. Soft loose surfaces such as shag carpet, loose sand or gravel, wet clay, and irregular surfaces such as cobblestones can significantly impede wheelchair movement. All four embodiments of the present invention comply with this section.

Section 4.7.4 of TAS' goes on to state that the textures of the surfaces on curb

¹ Texture on curb ramps, hazardous vehicular ways, and around reflecting pools, are presently suspended under ADAAG pending further study of warning systems due to concerns expressed by advocates and businesses about the use of round-based diagonally spaced truncated domes. Currently, ADAAG is governed by the Access ramps shall consist of exposed crushed stone aggregate, roughened concrete, rubber, raised abrasive strips, or grooves extending the full width and depth of the curb ramp. Surfaces that are raised, etched, or grooved in a way that would allow water to accumulate are prohibited. For purposes of warning, the full width and depth of curb ramps shall have light reflective value and texture that significantly contrasts with that of adjoining pedestrian routes.

Technical Memorandum 99-02 issued January 5, 1999 by the Texas Department of Licensing Regulation (TDLR) modified Section 4.7.4 by recognizing the need to form a stable framework in concrete surfaces for proper alignment and installation of paver inserts at curb ramps. TDLR will accept a border not exceeding four inches at the sides, top, and bottom of the curb ramp surface in lieu of extending the full length and width of the curb ramps as specified in Section 4.7.4. The border might be used to accommodate tile or brick. This extra four inches is not critical for the present invention, but is preferred. Technical Memorandum 99-15 issued by the TDLR on July 2, 1999 relates to

TAS Section 4.7.4 which requires curb ramps to have a light reflective value and surface texture that significantly contrasts with that of adjoining pedestrian routes. This memorandum advises that the only surface texture that TDLR is currently aware of that meets the intent of this standard are round-based truncated domes meeting the technical specifications of Section 4.29.2. Other textures such as grooves " deep and ³Λ" wide and 2" apart and arranged so that water will not accumulate, may be acceptable provided the surfaces are detectable underfoot. Other designs for surfaces that are detectable underfoot maybe submitted for consideration. The specifications of the first embodiment of the present invention comply with this solution described by the TDLR as having rectangular block shapes separated with grooves ^lA inch deep and ³/₄ inch wide and 2 inches apart; however, it is preferred that the width of the grooves be no greater than '/. inch so as to prevent wheelchair wheels and ladies' heels from getting stuck in the material. Where the grooves of the detectable warning system turn parallel with the

Board, the Department of Justice, and the Department of Transportation. However, TAS requires texture and light reflective value contrast on surfaces of curb ramps (TAS 4.7.4). dominant direction of travel, the groove width is decreased to % inch to allow for water drainage. In the second embodiment of the present invention, narrow ridges are used parallel to the dominant direction of travel to provide a comprehensive tactile wayfinding system for people with visual impairments. These narrow ridges are preferably 0.5 inch wide at their base, 0.2 inch high, 3 V₂ inches long, and spaced 2 inches apart on center and are readily distinguishable underfoot from other embodiments of this invention and the traditional round-based truncated domes.

In a third embodiment of the present invention, aligned raised-elongated truncated domes are used running parallel to the dominant direction of travel to give maximum detectability and directional cues while providing a more stable, supportive, and slip- resistant surface with fewer "bumps" than the traditional diagonally spaced round-based truncated domes. This embodiment is to be used where a tactile "stop-sign" is required and directional clues are desired. These elongated domes are preferably .9 inch wide at the base and .40 inch at the top, .20 inches high, 2.55 inches long, and spaced 2.35 inches apart on center, and 2.35 inches from a point .45 inch inside the base ends of an elongated dome to a point .45 inch inside of the base ends of the adjacent elongated domes.

In the fourth embodiment of the present invention, aligned raised elongated truncated domes, of lesser length than the third embodiment of the present invention, running parallel to the dominant direction of travel to give maximum underfoot detectability while providing a more stable, supportive and slip-resistant surface with fewer "bumps" than the traditional diagonally spaced round-based truncated domes. This embodiment is to be used where a tactile "stop-sign" is required and directional clues are not desired. These elongated domes are preferably 0.9 inch wide at the base and 0.40 inch at the top, 0.20 inches high, 1.75 inches long, and spaced 2.35 inches apart on center, and 2.35 inches from a point 0.45 inch inside the base ends of an elongated dome to a point 0.45 inch inside of the base end of the adjacent elongated domes.

Section 4.7.5 of the TAS states that if a curb ramp is located where a pedestrian must walk across the ramp, or where it is not protected by handrails or guardrails, it shall have flared sides. The TDLR has not accepted parallel public sidewalk curb ramps as illustrated in Fig. lg and as proposed in ADAAG except through an approved variance. Technical memorandum 99-11 issued on January 13, 1999 by the TDLR allowed for the parallel public sidewalk curb ramp without a variance.

Section 4.7.10 of the TAS and ADAAG concerns diagonal curb ramps as illustrated in Fig. la-Id. According to this section, if diagonal (or corner type) curb ramps have returned curbs or other well-defined edges, such edges shall be parallel to the direction of pedestrian flow. The bottom of the diagonal curb ramps shall have 48 inch (1220 mm) minimum clear space within the markings. If the diagonal curb ramps have flared sides, they shall also have at least 24 inch (610 mm) long segment of straight curb located on each side of the curb ramp and within the marked crossing. This gives a person with a sight disability an indication of where to cross a street, for example. Section 4.7.9 of the TAS and ADAAG provides for the location of curb ramps at marked crossings. In particular, the section provides that curb ramps at marked crossings shall be wholly contained with the markings, excluding any flared sides. The detectable warning and wayfinding systems of the present invention could be used in the mark to define the marked crossing. Specifically, if a person with a visual impairment is preparing to cross a diagonal or street, he or she would be able to detect this device if he or she begins to stray out of the marked crossing.

In addition, the accessibility standards provide in Section 4.29 that detectable warning systems required by sections 4.1 and section 4.7 comply with 4.29². Section 4.29.2 provides for detectable warnings on walking surfaces. A detectable warning is a standardized surface feature built in or applied to walking surfaces or other elements to warn visually impaired people of hazards in a circulation path. In this section, detectable warnings shall consist of raised (round based) truncated domes with a diameter of nominal 0.9 inches (23 mm)³, a height of nominal 0.2 inches (5 mm), and a center to

² Detectable warnings on curb ramps and hazardous vehicular areas, warnings at stairs, and at reflecting pools is reserved by ADAAG pending further study of systems (truncated domes have caused problems). However, TAS requires contrasting texture and light reflective value on curb ramps. Both TAS and ADAAG require detectable warnings on transportation platforms where drop-off occurs. (10.3.1(8)).

3

The diameter measurement in the present ADAAG and TAS is ambiguous in that it does not specify whether the diameter is to be measured at the bottom or top of the truncated domes. center spacing of nominal 2.35 inches (60 mm) and shall contrast visually with adjoining surfaces either light-on-dark or dark-on-light. According to this section, the material used to provide contrast shall be an integral part of the walking surface. Detectable warnings used on interior surfaces shall differ from adjoining walking surfaces in resiliency or sound-on-cane contact, according to Section 4.29.2. The first, third, and fourth embodiments of the present invention are designed to be used in any situation where there is a need for a detectable warning device and provide many advantages over the traditional round-based truncated domes.

One of the primary advantages of the first embodiment of the present invention over the traditional detectable warning device, the traditionally diagonally spaced round based truncated dome, is that this embodiment provides a more stable, supportive, slip resistant tactile warning surface. Although the grooves of this embodiment are not as detectable as truncated domes, its use, particularly in interiors, is more desirable because it reduces the possibility of trips and falls for sighted pedestrians, particularly women wearing high heals. As required by both ADAAG and TAS, in interior applications, the material used in this embodiment's integral walking surface must differ from adjoining walking surfaces in resiliency or sound on cane contact.

In the case of the second embodiment of the present invention, narrow ridges are used perpendicular or parallel to the dominant direction of travel to provide a comprehensive tactile directional wayfinding system for people with visual impairments. The primary advantage of this embodiment over the prior art, such as bar tiles and guidestrips, is that the directionallity, height, spacing, and width of its narrow ridges are more highly detectable and are more clearly discernable from other tactile warning devices. Tactile wayfinding devices must not be confused with detectable warning devices by persons with sight impairments.

In the case of the third embodiment of the present invention, elongated raised truncated domes are used to provide a tactile detectable warning device that also provides directional clues for persons with visual impairments. The primary advantages of this embodiment over the prior art of diagonally spaced round-based truncated domes, while being equally or more detectable underfoot, the elongated truncated domes of this embodiment provide directional clues, while the round-based domes do not. The elongated truncated dome surfaces of this embodiment have approximately three times more top bearing surface area than the traditional truncated round-based dome, thereby providing greatly increased support, stability, comfort, and slip-resistance when underfoot. Being aligned to run parallel with the predominant direction of travel provides a clear track between the elongated domes of this embodiment thereby minimizing vibration for wheelchairs. The traditional diagonally spaced round truncated domes do not have this feature. Further, this embodiment reduces the number of "bumps" caused by the traditional round-based dome edges by 40%, thereby reducing the potential for trips, falls, and wheelchair vibration. If in ice conditions, when truncated dome detectable warning surfaces are flooded with salt or sand and broomed for ice removal, such as on curb ramps, any water will collect below and between the domes where people stand. An advantage of the elongated truncated dome embodiment of the present invention over the traditional round-based truncated dome is that it provides approximately three times more slip-resistant standing surface above the icy water level than the traditional round based truncated dome.

In case of the fourth embodiment of the present invention, elongated raised truncated domes are used to provide a tactile detectable warning "stop sign" device, without directional clues, for persons with visual impairments. The primary advantage of this embodiment over the prior art of diagonally spaced round-based truncated domes, while being equally or more detectable underfoot, is the elongated truncated surfaces of this embodiment have approximately two and one half times more to bearing surface area than the traditional truncated round-based dome "dots", thereby providing greatly increased support, stability, comfort, and slip-resistance when underfoot. Being aligned to run parallel with the predominant direction of travel provides a clear track between the elongated domes of this embodiment thereby minimizing vibration for wheelchairs. The traditional diagonally spaced round truncated domes do not have this feature. Further, this embodiment reduces the number of "bumps" caused by the traditional round-based dome edges by 20%, thereby reducing the potential for trips, falls, and wheelchair vibration. If in ice conditions, when truncated dome detectable warning surfaces are flooded with salt or sand and broomed for ice removal, such as on curb ramps, any water will collect below and between the domes where people stand. An advantage of the elongated truncated dome embodiment of the present invention over the traditional round-based truncated dome is that it provides approximately two and one half times more slip- resistant standing surface above the icy water level than the traditional round based truncated dome.

The appendix to Section 4.29.2 of ADAAG and TAS provide for detectable warnings on walking surfaces. The material used to provide contrast should contrast by at least 70% light-on-dark or dark-on- light. For that reason the two preferred dark colors to use in all embodiments of the present invention are very dark brown and very dark grey. A very light tan and a very light grey are the two preferred light colors. Yellow is also preferred. Recent research indicates that the color safety yellow is so salient-even to persons having very low vision-that it is highly visible even when used in association with surfaces having light reflectance values differing by as little as 40%o. This safety yellow detectable warning surface having a 40% reflectance difference from new concrete was even subjectively judged more detectable than a darker warning surface which contrasted with new concrete by 86%. It has also been found that yellow or yellow- orange warning surfaces were preferred over black warning surfaces. Safety yellow is a color that is standardized for use as a warning in the pedestrian/highway environment according to U.S.-ANSI Z535.1-1991, 6.3 and Internationally-ISO 3864-1984(E). According to Section 4.29.2 contrast in percent is determined by:

Contrast = [(B,B₂) B,] x 100 where B, is the light reflectance value (LRV) of the lighter area and B₂ is the light reflectance value (LRV) of the darker area. In this formulation B, never equals 100 and B₂ is always greater than zero. As required by ADDAG and TAS, surface materials of all embodiments of the present invention will be integrally colored.

The present invention was designed to comply with TAS, ADAAG, Model Codes, and other state's standards for the purpose of creating visual and/or tactile cues at accessible route locations, such as ramps, hazardous areas, and the like. There are four six variations of the detectable warning system of the present invention. These variations involve a brick or concrete paving tile, brick or concrete pavers, stamped concrete, natural stone or stone composites, large precast assemblies, surface applied ridges, and mat configuration including rigid polymer and flexible polyurethane sheets and tiles. Any surface covering could be used. However, the type of surface covering may vary due to its destination. It is preferred that the tile and brick variations have a thickness of at least 2% inch. On a flat level surface of the six preferred grooved configurations of the first embodiment of the present invention, there is inset a plurality of rectangular block shapes with a surface texture. It is preferred that the rectangular block shapes be divided by grooves ! inch deep and ^lA inch wide and 2 inches apart on center running perpendicular to the dominant direction of travel. The tactile detectable warning system's drainage grooves' width preferably is decreased to % inch wide and 4 inches on center since these grooves run parallel to the dominant direction of travel. The reason for this is to reduce the potential for wheelchairs wheels, canes, walkers, and the like of becoming wedged into these drainage grooves. In the second embodiment of the present invention, narrow ridges are used perpendicular or parallel to the dominant direction of travel to give a comprehensive tactile directional wayfinding system for people with visual impairments. These ridges are preferably 0.5 inch wide, 0.2 inch high, 3 !/_ inches long, and spaced 2 inches apart on center. The third embodiment of the present invention utilizes raised elongated truncated domes that are .9 inch wide at the base and .40 inch at the top, .20 inch high, 2.55 inches long, spaced 2.35 inches apart on center, and 2.35 inches from a point .45 inch inside the base ends of an elongated dome to a point .45 inch inside of the base end of the adjacent elongated truncated domes to provide a highly detectable underfoot tactile warning system and directional clues at hazardous locations.

The fourth embodiment of the present invention utilizes elongated truncated domes that are 0.9 inch wide at the base and 0.40 inch at the top, 0.20 inch high, and 1.75 inches long, spaced 2.35 inches apart on center, and 2.35 inches from a point 0.45 inch inside the base ends of an elongated dome ridge to a point 0.45 inch inside of the base end of the adjacent elongated truncated domes to provide a highly detectable underfoot tactile warning system- non-directional "stop sign" at hazardous locations.

The texture of all embodiments of the present invention may utilize silicon carbide, sometimes referred to as carborundum, which is a crystalline material with colors that vary from green to black from industrial commerce. Silicon carbide has a diamondlike hardness and maintains a high thermal conductivity with low thermal expansion which makes it more resistant to thermal shock and therefore an important compound for use in refractory applications. At the present time, silicon carbide is used in the metallurgical, abrasive, and refractory industries in great quantities. In addition, silicon carbide is used for heating elements in electric furnaces, in electronic devices, and in various applications which take advantage of the compound's resistance to nuclear radiation damage.

When silicon carbide is used on a walking surface such as on a paving tile or brick paver, the walking surface is more slip-resistant. In addition, when the silicon carbide texture is added to the rectangular block, such as a brick paver, ridges, or elongated truncated domes, it appears to impede wear and last longer. Further, as prolonged pedestrian traffic begins to smoothen the walking surface of the present invention, the silicon carbide will become more exposed thereby maintaining the slip- resistance of its walking surface. Another advantage to the use of silicon carbide for the texture of the present invention is that sulfuric acid will not attack the silicon carbide therefore rendering the texture resistant to the effects of acid rain when used outside with exposure to the elements. While the preferred texture material is silicon carbide, any rough hardened stone material, such as granite, could be inset into the walking surface of a brick paver or paving tile, to enhance the conditions of the detectable warning system as long as the material surface is slip-resistant and has a tendency to impede wear. The texture could be a roughened surface of the rectangular block shapes, ridges, or elongated truncated domes, or an additive applied to the walking surface of the present invention.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel detectable warning and comprehensive wayfinding system for persons with disabilities. A further object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which meets the requirements of ADAAG, TAS, Model Codes, and other state accessibility standards.

It is another object of the present invention to provide a novel detectable warning and comprehensive wayfinding system which can be used in or along any hazardous area. Still another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which uses a surface texture to distinguish a hazard from a non-hazard.

Yet another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which utilizes a slip-resistant surface texture. Another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which can utilize a rough hardened stone material, such as silicon carbide or granite, as the surface texture.

Still another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which is designed to prevent the accumulation of water on walking surfaces.

Yet another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which utilizes a color contrast to distinguish from other adjoining pedestrian routes.

It is still another object of the present invention to provide a novel detectable warning and comprehensive wayfinding system which uses dark grey, dark brown, light grey, light tan colors, or yellow that will contrast with adjoining pedestrian routes.

A further object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which is portable or can be applied in place.

Yet another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which can be configured on a brick or concrete paving tile, a brick or concrete paver, wet concrete, natural stone or stone composites, large precast assemblies, surface applied ridges, or a mat including rigid polymer and flexible polyurethane sheets and tiles.

Another object of the present invention is to provide a novel detectable warning and comprehensive wayfinding system which utilizes ridges and elongated raised truncated domes for greater detectability, directional cues, and directional guidance.

In satisfaction of these and related objectives, Applicant's present invention provides a detectable warning and comprehensive wayfinding system for persons with disabilities. Applicant's invention permits its practitioner to provide a safer surface for persons with mobility disabilities and persons with visual impairments which will enable these people to detect accessibility routes and hazardous areas with visual or tactile cues. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. la is a perspective view of a concave curb ramp with flared sides showing placement of the preferred embodiment of the present invention utilizing brick or concrete paving tiles, brick or concrete pavers, natural stone or stone composites, or large precast assemblies.

Fig lb is a perspective view of a concave curb ramp with flared sides showing placement of the preferred embodiment in stamped concrete, mat configuration, surface applied ridges, or elongated truncated domes.

Fig. lc is a perspective view of a return curb ramp showing placement of the preferred embodiment of the present invention utilizing brick or concrete paving tiles, brick or concrete pavers, natural stone or stone composites, or large precast assemblies.

Fig. Id is a perspective view of a return curb ramp showing placement of the preferred embodiment of the present invention in stamped concrete, mat configuration, surface applied ridges, or elongated truncated domes. Fig. le is a perspective view of a built-up curb ramp showing placement of the preferred embodiment of the present invention utilizing brick or concrete paving tiles, brick or concrete pavers, natural stone or stone composites, or large precast assemblies.

Fig. If is a perspective view of a built-up curb ramp showing placement of the preferred embodiment of the present invention in stamped concrete, mat configuration, surface applied ridges, or elongated truncated domes.

Fig. lg is a perspective view of a parallel public sidewalk curb ramp showing placement of the preferred embodiment of the present invention utilizing brick or concrete paving tiles, brick or concrete pavers, natural stone or stone composites, or large precast assemblies. Fig. lh is a perspective view of a parallel public sidewalk curb ramp showing placement of the preferred embodiment of the present invention in stamped concrete, mat configuration, surface applied ridges, or elongated truncated domes.

Fig. 2a - Fig. 2d are plan views of different types of crosswalks with placement of the preferred embodiment of the present invention. Fig. 3a is a top view of a paving tile with rectangular block shapes.

Fig. 3b is a right side view of a paving tile with rectangular block shapes. Fig. 3c is a bottom side view of a paving tile with rectangular block shapes.

Fig. 4 is a perspective view of brick pavers with rectangular block shapes.

Fig. 5 is a perspective view of a rigid polymer and flexible polyurethane detectable warning mat with rectangular block shapes. Fig. 6a is a top view of a paving tile with surface texture on rectangular block shapes.

Fig. 6b is a right side view of a paving tile with surface texture on rectangular block shapes.

Fig. 6c is a bottom side view of a paving tile with surface texture on rectangular block shapes.

Fig. 7a is the preferred embodiment of the present invention's detectable warning system in use to detect hazards i.e. stairs

Fig.7b is the preferred embodiment of the present invention's detectable warning system in use to detect hazard i.e. reflecting pools. Fig. 7c is the preferred embodiment of the present invention's detectable warning system as it can be used on transportation platform edges bordering drop-offs.

Fig. 8a is a top view of a paving tile with ridges utilized in the second embodiment of the present invention.

Fig. 8b is a right side view of a paving tile ridges. Fig. 8c is a bottom side view of a paving tile with ridges.

Fig. 9a is a top view of a paving tile with elongated raised truncated domes utilized in the third embodiment of the present invention.

Fig. 9b is a right side view of a paving tile with elongated raised truncated domes utilized in the third embodiment of the present invention. Fig. 9c is a bottom side view of a paving tile with elongated raised truncated domes utilized in the third embodiment of the present invention.

Fig. 10a is a top view of a paving tile with another embodiment of elongated truncated domes utilized in the fourth embodiment of the present invention.

Fig. 10b is a right side view of a paving tile utilizing the elongated truncated domes of the fourth embodiment of the present invention.

Fig. 10c is a bottom side view of a paving tile utilizing the elongated truncated domes of the fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figure 1 a, a concave curb ramp 102a with flared sides 100 is shown utilizing paving tiles or brick pavers. According to the accessibility standards, the flared side 100 has a slope of 1:10. However if the mark 101a is less than 48 inches, then the slope of the flared side 100 shall not exceed 1 :12. The primary reason for this is so that someone in a wheelchair would be able to cross over the curb ramp 102a. In Texas, it is acceptable that the flared side 100 have color and texture contrast, but it is always preferable to keep the detectable warning system on the surface of the curb ramp 102a itself. Fig lb is the concave curb ramp 102a with a walking surface in stamped concrete, mat configuration, surface applied ridges or raised elongated truncated domes.

Fig. lc illustrates a return curb ramp 102b utilizing brick or concrete paving tiles, brick or concrete pavers, natural stone or stone composites, or large precast assemblies.

The returned curb ramp 102b is used when someone cannot walk across the curb. The returned curb 111 must be parallel with the direction the person is preparing to cross the street. The detectable warning system is placed on the surface of the return curb ramp

102b. Fig. Id shows the return curb ramp 102b with a walking surface in stamped concrete, mat configuration, surface applied ridges, or raised elongated truncated domes.

A built-up curb ramp 102c is shown in Fig. le. This built-up curb ramp 102c is commonly used in retrofit situations. The detectable warning system is placed on the surface of the built-up curb ramp 102c. Fig. If is the built-up curb ramp 102c with a walking surface in stamped concrete, mat configuration, or surface applied ridges.

In Fig. 1 g a parallel public sidewalk curb ramp 102d is shown. In this illustration, the detectable warning system is placed on both sides of the parallel public sidewalk curb ramp 102d. Fig. lh is the parallel public sidewalk curb ramp in stamped concrete, mat configuration, surface applied ridges, or raised elongated truncated domes.

Fig. 2a through Fig. 2d illustrate different scenarios for crosswalks. In these scenarios not only is the detectable warning system used on the various types of curb ramps, but on the cross-marking 107 as well. This is important because once a person with visual impairments comes off the curb ramp and into the street, if he or she strays, he or she will pick up the detectable warning system. Referring to Fig. 3a - Fig. 3c, a top, right side, and bottom side view respectively of a paving tile 103 utilizing the first embodiment of the present invention is shown. The paving tile 103 is preferably approximately a 12 inch x 12 inch x 2% inch block. The paving tile 103 may have a surface texture of rough hardened material (not shown), such as silicon carbide or granite used as an additive to the walking surface of the paving tile 103, and of sufficient size and thickness for the intended or related use. The paving tile 103 may vary in thickness depending on where it is being used. However, a minimum of 2% inches is preferred for heavy pedestrian traffic. In this embodiment, the paving tile would be molded in concrete that has a compressive strength greater than 8,000 psi (pounds per square inch), a water absorption rate of less than 5%, and that meets or exceeds ASTM C-938 and freeze-thaw testing per section 8 of ASTM C-67. The paving tile 103 will have an adequate number of Vβ inch spacer ribs 108 to automatically provide minimum joint width between paving tiles 103. It is recommended that paving tiles 103 be installed over a minimum V/β inch bed of washed concrete sand, tapped to a uniform level, and the joints filled with sand. However, where heavy pedestrian traffic is anticipated, it is recommended that the pavers are set in a 2 inch thick mortar bed over a 2 inch layer of fibrous concrete over a 2 inch sand cushion over a 6 inch prepared subgrade. Mechanical fasteners and structural adhesives may also be utilized in some installations. The rectangular block shapes 104 are formed by deep grooves 109, which are ^lA inch deep, preferably 5 inch wide and 2 inches on center extending across the surface of the paving tile 103 perpendicular to the dominant direction of travel. There are preferably ^lA inch deep, % inch wide, and 4 inches on center drainage grooves 110 running across the paving tile 103 parallel to the dominant direction of travel. Both the deep grooves 109 and the drainage grooves 110 have beveled sides to facilitate the molding process and to reduce the possibility that wheelchair wheels, high heels, walkers, and canes will get stuck in the grooves.

Fig. 4 is a perspective view of brick pavers 105. The brick pavers 105 used in one embodiment of the invention would be molded in the same concrete material described above for the paving tile 103. The brick paver 105 is approximately a 12 inch x 6 (or 4) inch block. The brick paver 105 may vary in thickness depending on where it is being used, however a minimum of 2% inches is preferred with typically 4-6 inches of compacted subbase (not shown) for light vehicular and pedestrian traffic. The brick paver 105 will have Va inch spacer ribs 108 to automatically provide minimum joint width between the brick pavers 105. It is recommended that the brick pavers 105 be installed over a minimum l¹/β inch bed of washed concrete sand, tapped to a uniform level, and the joints filled with sand. However, paver setting methods should be determined after analysis of soil conditions, traffic anticipated, etc. Where heavy pedestrian traffic is anticipated, it is recommended that the brick pavers are set in a 2 inch thick mortar bed over a 2 inch layer of fibrous concrete over a 2 inch sand cushion over a 6 inch prepared subgrade. Mechanical fasteners and structural adhesives may also be utilized in some installations. The rectangular block shapes 104 are formed by deep grooves 109 of A inch deep, preferably Vi inch wide, and 2 inches on center extending across the surface of the brick paver 105 perpendicular to the dominant direction of travel. There are preferably % inch deep, % inch wide, and 4 inches on center drainage grooves 110 running across the brick paver 105 parallel to the dominant direction of travel. Both the deep grooves 109 and the drainage grooves 110 have beveled sides to facilitate the molding process and to reduce the possibility that wheelchair wheels, high heels, walkers, and canes will get stuck in the grooves.

In Fig. 5, a polyurethane detectable warning mat 106 is shown. This mat 106 is useful because it warns visually impaired pedestrians that they are about to enter a dangerous vehicular area. This mat 106 would be used primarily for retrofit situations where a curb ramp has previously been constructed but no texture or color contrast had been used thereon. Essentially this mat 106 would be placed on the curb ramp and glued down to solve the lack of texture and color contrast problem. The mat 106 is preferably flexible, but does not have to be, and is of sufficient size and thickness for its intended or related use. The mat 106 should be sufficiently pliable to conform to the shape of the curb ramp. The mat 106 preferably conforms to the dimensions currently set for curb ramps, but this is not critical. The typical curb is 6 inches high and the curb ramp surface must be a minimum of 36 inches wide. Fig. 6a - Fig. 6c show a slip-resistant surface texture such as silicon carbide or granite being used as an additive to the walking surface of paving tile 103. This surface texture could be added to all other embodiments of this invention. Another possible way to create the texture would be to mold or stamp a slip-resistant surface texture into the walking surface of all embodiments of this invention.

Fig. 7a - Fig. 7c is the detectable warning as it can be used in some example hazardous areas. Fig. 7a illustrates how the detectable warning system can be placed next to a staircase to alert an individual with visual impairments to the danger ahead. Fig. 7b is the warning system next to a reflecting pool. In Fig. 7c the detectable warning system is shown next to a train platform edge bordering a drop-off.

The second embodiment of the present invention is shown in Fig. 8a-8c which illustrates a top, right side and bottom side view respectively of a brick or concrete paving tile 103 with narrow ridges 112. This embodiment resembles the first embodiment but provides for narrow ridges 112 rather than deep groves 109 perpendicular or parallel to the dominant direction of travel. The paving tile 103 is preferably approximately a 12 inch x 12 inch x 2 3/8 inch block. The paving tile 103 may have a surface texture of rough hardened material (not shown), such as silicon carbide or granite used as an additive to the walking surface of the paving tile 103, and of sufficient size and thickness for the intended or related use. The paving tile 103 may vary in thickness depending on where it is to be used. In this embodiment , the paving tile 103 would be molded in concrete that has a compressive strength greater than 8,000 psi (pounds per square inch), a water absorption rate of less than 5%, and that meets or exceeds ASTM C-938 and freeze thaw testing per section 8 of ASTM C-67. The paving tile 103 will have an adequate number of 1/8 inch spacer ribs 108 to automatically provide minimum joint width between paving tiles 103. It is recommended that the paving tiles 103 be installed over a minimum 1 1/8 inch bed of washed concrete sand, tapped to a uniform level, and the joints filled with sand. Where heavy pedestrian traffic is anticipated, it is recommended that the pavers are set in a 2 inch thick mortar bed over a 2 inch layer of fibrous concrete over a 2 inch sand cushion over a 6 inch prepared subgrade. Mechanical fasteners and structural adhesives may also be utilized in some installations.

Narrow ridges 112 are provided that run perpendicular or parallel to the dominant direction of travel. The narrow ridges 112 in this embodiment are preferably approximately ^XA inch wide, 0.2 inch high, 3 ^XA inches long, and spaced 2 inches apart on center. Such narrow ridges 112 are readily detectable underfoot from the traditional round-based truncated domes and the other embodiments of the present invention and provide a comprehensive tactile directional wayfinding system not a tactile warning "stop sign" device to persons with visual impairments. The narrow ridges 1 12 are preferably truncated on top for more bearing. The truncated tops of the narrow ridges 1 12 can facilitate snow removal as an operator would be able to scrape the snow parallel to the narrow ridges 112. These narrow ridges 112 may also have a surface texture of rough hardened material (not shown) such as silicon carbide or granite used as an additive. In addition, the narrow ridges 112 are directional which provides clues and directional guidance to long canes as well as underfoot, which is particularly useful for persons with visual impairments. These clues are not present with the traditional round-based truncated domes. Clear tracks 113 run across the paving tile 103 preferably perpendicular to the dominant direction of travel, however placement parallel to the dominant direction of travel may be used as well. These tracks 113, which are preferably approximately one inch wide, are useful in keeping wheelchairs on ramp surfaces in conjunction with beveled ends 115 of the narrow ridges 112. When the narrow ridges 112 run parallel to the dominant direction of travel a clear track is provided for wheelchair passage over the surface of the wayfinding system. These clear tracks 113 also facilitate water drainage between the beveled ends 115 of the narrow ridges 112. This second embodiment is useful on not only brick or concrete paving tiles, but on brick or concrete pavers, stamped concrete, natural stone or stone composites, large precast assemblies, surface applied ridges, and mats including rigid polymer and flexible polyurethane sheets and tiles.

The third embodiment of the present invention is shown in Fig. 9a-9c which illustrates a top, right side and bottom side view respectively of a brick or concrete paving tile 103 with raised elongated truncated domes 116. The paving tile 103 is preferably approximately a 12 inch x 12 inch x 2 3/8 inch block. The paving tile 103 may have a surface texture of rough hardened material (not shown), such as silicon carbide or granite used as an additive to the walking surface of the paving tile 103, and of sufficient size and thickness for the intended or related use. The paving tile 103 may vary in thickness depending on where it is to be used. In this embodiment , the paving tile 103 would be molded in concrete that has a compressive strength greater than 8,000 psi (pounds per square inch), a water absorption rate of less than 5%, and that meets or exceeds ASTM C-938 and freeze thaw testing per section 8 of ASTM C-67. The paving tile 103 will have an adequate number of Vβ inch spacer ribs 108 to automatically provide minimum joint width between paving tiles 103. It is recommended that the paving tiles 103 be installed over a minimum l¹/β inch bed of washed concrete sand, tapped to a uniform level, and the joints filled with sand. However, where heavy pedestrian traffic is anticipated, it is recommended that the pavers are set in a 2 inch thick mortar bed over a 2 inch layer of fibrous concrete over a 2 inch sand cushion over a 6 inch prepared subgrade. Mechanical fasteners and structural adhesives may also be utilized in some installations.

Raised elongated truncated domes 116 are aligned and run parallel to the dominant direction of travel. The raised elongated truncated domes 116 in this embodiment are preferably approximately .9 inch wide at the base and .40 inch at the top, .20 inch high, 2.55 inches long at the base, spaced 2.35 inches apart on center, and 2.35 inches from a point .45 inch inside the base end of a ridge to a point .45 inch inside of the end of the adjacent raised elongated truncated dome. The width of the raised elongated truncated domes 116 of this embodiment of the present invention provides approximately three times more bearing surface support to feet and therefore appears to provide more secure, slip-resistant, and comfortable footing than traditional round-based truncated domes. Such raised elongated truncated domes 116 are readily detectable underfoot and because of their exaggerated elongated shape appear to provide directional clues to long canes as well as underfoot for signed impaired persons when this feature is needed. This feature is not present with traditional round-based truncated domes. Further, this embodiment reduces the number of "bumps" caused by the traditional round-based truncated domes by approximately 40% thereby considerably reducing the adverse impacts on persons such as trips and falls for sighted pedestrians, particularly women wearing high heels, as well as difficulty for wheelchair users and persons with mobility impairments in traversing ramps. Since the elongated truncated domes of this embodiment of the present invention are aligned and run parallel to the dominant direction of travel, they provide a clear track and are significantly less bumpy to wheelchairs than traditional round-based truncated domes, particularly since the traditional round-based truncated domes are usually spaced diagonally and not aligned. The raised elongated truncated domes 116 are preferably truncated on top for more bearing. The truncated tops of the raised elongated truncated domes 116 can facilitate snow removal as an operator would be able to scrape the snow diagonally across the raised elongated truncated domes 116. This feature is not present with traditional round- based truncated domes. These raised elongated truncated domes 116 may also have a surface texture of rough hardened material (not shown) such as silicon carbide or granite used as an additive. Clear tracks 117 run across the paving tile 103 between the ends 118 of the elongated truncated domes 116 preferably perpendicular to the dominant direction of travel, however placement parallel to the dominant direction of travel may be used as well. These tracks 117, which are preferably approximately 1.75 inches wide, are useful in keeping wheelchairs rolling straight when being wheeled across the severe cross-slope encountered when crossing perpendicular over curb ramp surfaces in conjunction with beveled ends 118 of the raised elongated truncated domes 116. This third embodiment is useful on not only brick or concrete paving tiles, but on brick or concrete pavers, stamped concrete, natural stone or stone composites, large precast assemblies, surface applied elongated truncated domes, and mats including ridged polymer and flexible polyurethane sheets and tiles.

The fourth embodiment of the present invention is shown in Fig. 10a - 10c which illustrates a top, right side, and bottom side view respectively of a brick or concrete paving tile 103 which also utilizes a raised elongated truncated dome 119. This embodiment resembles the third embodiment of the present invention, but the elongated dome of the fourth embodiment has a shorter length. Thereby this embodiment does not provide directional clues where such clues are not desirable due to being used as purely a detectable warning "stop sign", not a wayfinding device.

The elongated truncated domes 119 in this embodiment are preferably 0.9 inch wide at the base and 0.40 inch at the top, 0.20 inch high, 1.75 inches long at the base, spaced 2.35 inches apart on center, and 2.35 inches from a point 0.45 inch inside the base end of an elongated truncated dome to a point 0.45 inch inside of the end of the adjacent truncated domes. The width and greater length of the elongated truncated domes of this embodiment of the present invention provide approximately two and one half times more bearing surface support to feet and therefore appear to provide more secure footing than traditional round based truncated domes.

Further this embodiment reduces the number of "bumps" caused by the traditional round-based truncated domes by approximately 20% thereby reducing the adverse impacts on persons such as trips and falls for sighted pedestrians, particularly women wearing high heals, as well as difficulty for wheelchair users and persons with mobility impairments in traversing ramps. Since the elongated truncated domes 119 of this embodiment of the present invention are also aligned and run parallel to the dominant direction of travel, they provide a clear track and are significantly less bumpy to wheelchairs than traditional round based truncated domes, particularly since the traditional round based truncated domes are usually spaced diagonally and not aligned. The elongated truncated domes 119 are preferably flat on top for more bearing. These elongated truncated domes 119 may also have a surface texture of rough hardened material (not shown), such as silicon carbide or granite used as an additive. Clear tracks 120 run across the paving tile 103 preferably perpendicular to the dominant direction of travel, however placement parallel to the dominant direction of travel may be used as well. These tracks 120, which are preferably approximately 1.75 inches wide, are useful in keeping wheelchairs rolling straight when being wheeled across the severe cross-slope encountered when crossing perpendicular over curb ramp surfaces in conjunction with beveled ends 118 of the elongated truncated domes 119.

This fourth embodiment, as with the third embodiment of the present invention, is useful on not only brick or concrete paving tiles, but on brick or concrete pavers, stamped concrete, natural stone or stone composites, large precast assemblies, surface applied elongated truncated domes, and mats including ridged polymer and flexible polyurethane sheets and tiles.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.

Claims

CLAIMS I claim:

1. A detectable warning and way finding system for persons with disabilities

comprising:

a walking surface with at least one level surface;

a surface texture dispersed over said walking surface; and

a plurality of ridges placed appropriately on said walking surface to provide

warning and directional clues underfoot and by long cane to said persons with visual

impairments.

2. The way finding system of Claim 1 wherein said walking surface is

selected from the group consisting of tiles, pavers, stamped concrete, natural

stone or stone composites, large precast assemblies, surface applied ridges,

and mats including rigid polymer and flexible polyurethane sheets and tiles.

3. The way finding system of Claim 2 wherein said surface texture is

designed to be in compliance with TAS and ADAAG.

4. The way finding system of Claim 3 wherein said surface texture is

dispersed over exposed surfaces of said plurality of ridges.

5. The way finding system of Claim 4 further comprising tracks which run

across said walking surface.

6. The way finding system of Claim 5 wherein said ridges run parallel to the

dominant direction of travel.

7. The way finding system of Claim 6 further comprising beveled ends located

at the ends of each of said ridges.

8. The way finding system of Claim 7 wherein said tracks are one inch wide.

9. The way finding system of Claim 8 wherein said ridges are .50 inch wide.

10. The way finding system of Claim 9 wherein said ridges are 2 inches apart.

11. The way finding system of Claim 10 wherein said ridges are at least 0.2 inch

high.

12. The way finding system of Claim 11 wherein said ridges are at least

3.5 inches long.

13. The way finding system of Claim 12 wherein said tiles further comprise

spacer ribs which automatically provide minimum joint width between said

tiles.

14. The way finding system of Claim 13 wherein said spacer ribs are at least Vβ

inch in width.

15. The way finding system of Claim 14 wherein said surface texture is

slip-resistant material.

16. The way finding system of Claim 15 wherein said surface texture is a

rough hardened stone.

17. The way finding system of Claim 16 wherein said surface texture is silicon

carbide.

18. The way finding system of Claim 17 wherein said surface texture is

granite.

19. A detectable warning system for persons with disabilities comprising:

a walking surface with at least one level surface;

a surface texture dispersed over said walking surface; and

a plurality of aligned raised elongated truncated domes placed appropriately

on said walking surface to provide detectability of said warning system in hazardous

areas.

20. The detectable warning system of Claim 19 wherein said walking surface is

selected from the group consisting of tiles, pavers, stamped concrete, natural

stone or stone composites, large precast assemblies, surface applied ridges,

and mats including rigid polymer and flexible polyurethane sheets and tiles.

21. The detectable warning system of Claim 20 wherein said surface texture is

designed to be in compliance with TAS and ADAAG.

22. The detectable warning system of Claim 21 wherein said surface texture is

dispersed over exposed surfaces of said plurality of said aligned raised

elongated truncated domes.

23. The detectable warning system of Claim 22 further comprising tracks which

run across said walking surface.

24. The detectable warning system of Claim 23 wherein said aligned raised

elongated truncated domes run parallel to the dominant direction of travel.

25. The detectable warning system of Claim 24 wherein said tracks are 1.75

inches wide.

26. The detectable warning system of Claim 25 wherein said aligned raised

elongated truncated domes are 2.35 inches apart.

27. The detectable warning system of Claim 26 wherein said aligned raised

elongated truncated domes are 0.9 inch wide.

28. The detectable warning system of Claim 27 wherein said aligned raised

elongated truncated domes are 0.20 inches high.

29. The detectable warning system of Claim 28 wherein said aligned raised

elongated truncated domes are at least 1.75 inches long.

30. The detectable warning system of Claim 29 wherein said walking surface

further comprises spacer ribs which automatically provide minimum joint

width between said walking surfaces.

31. The detectable warning system of Claim 30 wherein said spacer ribs are at

least 1/8 inch in width.

32. The detectable warning system of Claim 31 wherein said surface texture is

slip-resistant material.

33. The detectable warning system of Claim 32 wherein said surface texture is

rough hardened stone.

34. The detectable warning system of Claim 33 wherein said surface texture is

silicon carbide.

35. The detectable warning system of Claim 33 wherein said surface texture is

granite.

36. The detectable warning system of Claim 35 wherein said aligned raised

elongated truncated domes are spaced 2.35 inches from a point 0.45 inch

inside the ends of said aligned raised elongated truncated dome to a point

0.45 inch inside of the end of an adjacent aligned raised elongated truncated dome.

37. The detectable warning system of Claim 36 wherein said aligned raised

elongated truncated domes are 2.55 inches long to permit way finding by

said persons with disabilities.