Kenneth L. Stewart

October 25, 2002

Council of Citizens with Low Vision International


Subject: Guidelines for Public Rights-of-way Dear Board Members:

Following are comments on the Access Board’s Draft Guidelines for accessible public rights-of-way. I regret that I have not included specific references by Section number but the absence of an index or table of contents in the draft makes it quite arduous to locate particular entries during preparation of this statement.

DETECTABLE WARNING STRIPS

A requirement for tactually and visually detectable warning strips on the street edge of every curb ramp is very important.

Full-height curbing not only provides for road drainage and safety protection for all pedestrians, it also provides valuable locational and directional, information for pedestrians with limited or no vision. The curb is, of course, detectable topographically but it is also often tactually distinctive and is a visual element creating a shadow line for many low vision travelers.

Any curbing removed to permit the street-crossing access essential for wheelchair users, also removes a crucial street feature for vision impaired pedestrians. There must be a new element added to replace that important feature. The detectable strip must in all instances be at the border between pedestrian territory and the area where motor vehicles are moving. Visual detectability is established by light vs. dark contrast. The meeting line of the ramp and the roadway is the best place for the visual contrast to appear, a white detectable strip abutting an asphalt road surface, for example. The necessary visual contrast can also be accomplished internally with a white four-inch border against a black interior detectable strip, for example.

ACCESSIBLE PEDESTRIAN SIGNALS

The Draft Guidelines section requiring accessible pedestrian signals is quite well formulated and identifies very effectively the characteristics of appropriately designed and positioned APS’s.

Criticisms offered in opposition to the installation of accessible pedestrian signals are not germane to the present generation of devices which are not loud enough to disturb anyone, not ambiguous so as to confuse anyone, not stigmatizing in any way (actually they reinforce compliant street behavior by the general population) not distracting to pedestrians listening for other traffic cues and, are quite modest in cost, especially when compared to the total cost of signalizing an intersection for vehicles and the general pedestrian public

ROUNDABOUTS

The Draft Guidelines set an appropriate tone for the design of roundabouts. These intersection configurations have been demonstrated to move vehicular traffic through converging streets more efficiently and more safely than conventional intersections and therefore are a reasonable street design in some locations. However, they do not accommodate all categories of pedestrians without significant supplementary features. Thus a particular roundabout may be legitimately classified as a vehicles-only site with all pedestrian use prohibited. Typically in this circumstance a signalized intersection nearby is a reasonable alternate route for all pedestrians. Roundabouts which accept some pedestrians must accommodate all pedestrians with necessary features to do so safely

EDGE DETECTION ALONG RIGHTS-OF-WAY

It is extremely valuable to any person traveling by long white cane or by dependence upon very limited vision, to continuously detect at least one edge of the pedestrian access route.

At street crossings, high contrast crosswalk markings create effective visual edges (e.g., white stripes on dark pavement), and the Draft Guidelines should encourage research and experimentation on ways of making the stripes tactually detectable in a form which can withstand traffic wear and snowplows. The ideal stripe would have an outer edge distinguishable from an inner edge straight edge versus serrated, for example. In that way, the tactual or visual detection of lust one of the stripes would orient the traveler as to which side of that stripe to move.

The provision of a continuous edge, or shoreline, along a sidewalk is more difficult to assure. It too though is an important access feature. The Board’s Guidelines work in that direction by limiting street furniture to just one side zone of the pedestrian access route. Adding a visually and tactually detectable element along the clear side of the sidewalk would be particularly helpful where the route passes alongside an open area with a surface similar to the sidewalk. That circumstance is confronted by a vision impaired pedestrian walking by a large paved parking lot that blends smoothly into the sidewalk with no raised border elements such as a fence, bollards, or wheel blocks. A low vision traveler also confronts this problem when passing a service station with wide vehicle-approach aprons abutting the sidewalk.

SIDEWALK FURNITURE VISIBILITY

The Guidelines appropriately regulate overhangs on sidewalk appurtenances so that a long cane will detect obstructions. The Guidelines also should prescribe high visual contrast so that these elements are detectable visually as well. The concrete bench placed on a concrete sidewalk is a safety hazard to a low vision pedestrian. A simple solution like making the vertical members in the bench black, establishes the needed visual detectability simply and economically. Likewise a curbside bollard which is black is very helpful. The current common practice of using galvanized metal elements or painting vertical sign stanchions and parking meters grey, is the least helpful. Mid-tones are much less detectable than either visual extreme, light or dark.

LIGHTING

The type and quantity of artificial lighting provided along the pedestrian access route are very important to low vision travelers. While needs vary from person to person, several generalizations can be made-- High glare sources are difficult; lights which shine dire into the eye are undesirable; intermittent fixtures creating alternating bright and shadowy areas are not helpful.

Underpasses or other route segments which depend on artificial illumination at all times, should when possible have light intensity levels which adjust by time of day. The adjustment should mimic the exterior ambient lighting, that is, in bright daylight the passage should have bright lighting, and subdued lighting at night when the pedestrian’s eyes will be adapting from a dim ambient conditions and returning to a dimly lit exterior area after departing the underpass.

CONSTRUCTION SITE DETECTABILITY

Temporary construction sites must be required to mark the route so as to be detectable by cane and by limited vision. High contrast, typically black and white striped elements are necessary, as are cane detectable lower edges on barriers. Barricades with “feet” extending outward from vertical portions should be prohibited. Temporary coverings over sidewalk portions such as plywood panels, must have beveled edges and should be made very conspicuous by high visibility edges, black or white.

“PED-NEX" LOCATION

Where accessible pedestrian signals are installed, the site of the tactual and audible information the the "ped-nex" should be required close to the curb. The locator tone and vibrating arrow lose much of their usefulness to the vision impaired traveler who must navigate to the crosswalk from atop the sidewalk or behind it. At a pedestrian-actuated site, a wheelchair user would access the push button from a side, or use braking to operate the button from the ramp slope. Thus, in this situation there is a trade-off benefiting a large group of disabled pedestrians and inconveniencing some others.

MORE IS NOT ALWAYS BETTER

More of an accessibility feature does not always make for a better accessibility outcome. Several examples will illustrate.:

1) Wider curb ramps to accommodate two mobility impaired travelers moving side by side results in even more of the curb removal which diminishes the usability of the crossing for the vision impaired pedestrian.

2) A very wide crosswalk (one whose side stripes are far apart) is more difficult to use than a crosswalk with stripes which are reasonably close together, if the low vision pedestrian can only see one stripe of a broad crosswalk.

3) An elevator with two floor selection panels mounted low is less accessible for the vision impaired population than one with one panel low for people with restricted reach and one higher. A Braille user reads with the heel of the hand below the reading place, and many low vision elevator users read floor selections visually by looking very closely. In both instances, the presence of only low mounted panels is an accessibility challenge.

4) Increasing the intensity of artificial lighting can reach a level where glare or simply the total illumination reduces the functioning of some low vision pedestrians. Moderate and evenly distributed, lighting is generally recommended for the accessibility of the greatest number of people.

MYTHS ABOUT LOW VISION

There are some low vision pedestrians with good color perception who like yellow markings. But, contrary to myth, there are many low vision travelers with little or no color perception. For them, yellow used on a light surface such as new concrete, beige floor tiling, or pink marble payers, it is invisible. Yellow can work for all low vision pedestrians if it is used as the light component adjacent to a dark component. A yellow detectable warning strip at the edge of a dark asphalt road can be effective.

Contrary to myth, raised letter text signage is not useful for low vision pedestrians. While raised numerals are functional, in a dimly lit hotel corridor on quest rooms for example, no vision impaired person has yet been found who reads text signage by feeling the raised lettering. The features of text signage which make the information accessible to the low vision community are- size and visual contrast. Further, light letters on dark background are preferred if the characters are also raised. Otherwise, shadows from nearby light sources can darken the light background inside a character (obscuring the difference between an upper case “B” and an up case “R” for example.).

It is also myth that gently sloping flares aside curb ramps are helpful to low vision pedestrians. In fact a steeper sloping side flare can be more visually detectable, can be more easily avoided by an ambulatory pedestrian with an unsteady gait and can be less of an obstacle to the placement of other accessibility elements adjacent to curb ramps. A steeper ramp flare also has the advantage of removing less full-height curbing near the ramp. Further, the detectable warning strip on the ramp itself will aid in calling attention to the location of flares. The Access Board should rethink the standard which calls for very gradual flares.

VISIBILITY OF STAIRWAYS

Among the low vision population, the single most frequently voiced complaint about the built environment, is that stairs are hard to see. The Access Board should rectify the omission in the Final Draft ADAAG released in April of 2002, and specify high visual contrast marking on the nose of each stair tread on all steps in the public right-of-way. Embedding a white appearance in the front three or four inches of each dark surfaced stair tread would greatly improve the safety of stairways for low vision people traveling independently.

Sincerely,

Kenneth L. Stewart
CCLVI Representative to the PROWAAC Member CCLVI Board of Directors