36 CFR Parts 1190 and 1191 ADA and ABA Accessibility Guidelines - Preamble (Discussion of Comments and Changes)

406 Curb Ramps

Section 406 provides requirements specific to curb ramps and also applies requirements for other types of ramps covered by section 405. These include specifications for running slope, surface, clear width, and wet conditions. Consistent with the scope of the guidelines, these requirements apply to facilities on sites. The Board will address and invite comment on requirements for curb ramps located in public streets and sidewalks in upcoming rule making to develop supplementary guidelines specific to public rights-of-way. This supplement will be proposed for public comment based on recommendations from the Board’s Public Rights-of-Way Access Advisory Committee, which was comprised of representatives from the transportation industry, Federal, State and local government agencies, the disability community, and design and engineering professionals. This committee’s recommendations are contained in a report, "Building a True Community," which was submitted to the Board in January 2001.

Provisions for curb ramps in section 406 have been revised to:

• clarify requirements for cross slope (406.1)

• modify specifications for side flares (406.3) and landings (406.4)

• delete unnecessary language concerning handrails (406.4 in the proposed rule)

• clarify the specified location of curb ramps (406.5)

• change specifications for diagonal curb ramps (406.6)

Comment. Comments indicated that specifications for cross slope (1:48 maximum) are not referenced in the curb ramp section.

Response. In the final rule, the Board has clarified that curb ramps, like other elements of accessible routes, cannot have a cross slope steeper than 1:48, by adding a reference to the cross slope specification for ramps in section 405.3.

Section 406.3 addresses the sides of curb ramps and specifies that side flares, where provided, have a slope of 1:10 maximum. In the proposed rule, this provision required flared sides where pedestrians must walk across the curb ramp. Returned sides were permitted where pedestrians would not normally walk across the ramp. In the final rule, this distinction has been removed. However, curbs with returned sides remain an alternative to flared sides. In addition, the specification for shallower (1:12) side flares for curb ramps with limited space at the top has been removed in conjunction with revisions to the criteria for landings (406.4).

Comment. Commenters advised that landings should be specified at the top of curb ramps.

Response. Section 406.4 is new to the final rule in clarifying requirements for landings at the top of curb ramps. Curb ramps must be connected by an accessible route which, in effect, requires space at least 36 inches in length at the top of curb ramps. Otherwise, maneuvering at the top of ramps would require turning on the flared sides. Landings must also be as wide as the curb ramp they serve. The proposed rule specified that side flares of 1:12 maximum must be provided when space at the top of curb ramps is less than 48 inches long. This specification has been removed. However, a similar exception has been added for alterations. Under this exception, 1:12 maximum side flares are required where there is no landing at the top of curb ramps. This exception was provided to address situations where existing space constraints or obstructions may prohibit a landing at the top of curb ramps.

Comment. Commenters advised that landings should be specified at the top of curb ramps.

Response. Section 406.4 is new to the final rule in clarifying requirements for landings at the top of curb ramps. Curb ramps must be connected by an accessible route which, in effect, requires space at least 36 inches in length at the top of curb ramps. Otherwise, maneuvering at the top of ramps would require turning on the flared sides. Landings must also be as wide as the curb ramp they serve. The proposed rule specified that side flares of 1:12 maximum must be provided when space at the top of curb ramps is less than 48 inches long. This specification has been removed. However, a similar exception has been added for alterations. Under this exception, 1:12 maximum side flares are required where there is no landing at the top of curb ramps. This exception was provided to address situations where existing space constraints or obstructions may prohibit a landing at the top of curb ramps.

The proposed rule noted that handrails are not required on curb ramps (406.4 in the proposed rule). This language, though accurate, has been removed as unnecessary since the technical provisions for curb ramps in section 406 do not include or reference requirements for handrails.

Section 406.5 specifies the location of curb ramps at marked crossings. In the final rule, requirements for the general location of curb ramps that were provided at [DOT ADA Standards] section 406.8 in the proposed rule have been integrated into this provision for simplicity. As reformatted, section 406.5 covers the location of curb ramps, including at marked crossings.

Comment. Curb ramps must be located so that they do not project into vehicular traffic lanes or parking spaces and access aisles. Commenters noted that this requirement should be clarified to apply not only to the run of the curb ramp, but also to flared sides, where provided.

Response. Consistent with the intent of the requirement in section 406.5, the Board has clarified that the specified location applies to curb ramps "and the flared sides of curb ramps."

Comment. Section 406.6 provides specifications for diagonal (or corner type) curb ramps. These curb ramps must have a 48 inch minimum clear space at the bottom. Comments advised that this space should be provided outside active traffic lanes of the roadway so that persons traversing the ramp are not in the way of oncoming traffic from either direction at an intersection.

Response. Clarification has been added in the final rule that the clear space at the bottom of diagonal curb ramps must be located "outside active traffic lanes of the roadway."

Comment. Requirements for diagonal curb ramps in section 406.6 also specify that a segment of straight curb at least 2 feet long must be provided on each side of the curb ramp and within the marked crossing. This portion of curb face provides a detectable cue to people with vision impairments traveling within the crosswalk. Comments noted that this segment of curb does not have to be horizontally straight to provide such a cue and that achieving straight segments two feet long within marked crossings is very difficult under standard intersection design conventions.

Response. The requirement in section 406.6 that the 2 foot curb segment aside diagonal curb ramps be "straight" has been removed. The segment can be provided at arced portions of the curb, but must still be located within marked crossings.

Comment. Comments, most from groups representing persons with vision impairments, called attention to the need for detectable warnings at curb ramps, blended curbs, and cut-through islands. They requested that such a requirement be reinstated in the final rule. A few comments opposed such a change.

Response. The original ADAAG contained a requirement that curb ramp surfaces have a raised distinctive pattern of truncated domes to serve as a warning detectable by cane or underfoot to alert people with vision impairments of the transition to vehicular ways (ADAAG 4.7.7). This warning was required since the sloped surfaces of curb ramps remove a tactile cue provided by curb faces. In response to concerns about the specifications, the availability of complying products, proper maintenance such as snow and ice removal, usefulness, and safety concerns, the Board, along with the Department of Justice (DOJ) and the Department of Transportation (DOT), suspended the requirement for detectable warnings at curb ramps and other locations pending the results of a research project sponsored by the Board on the need for such warnings at these locations.²² The research project showed that intersections are very complex environments and that pedestrians with vision impairments use a combination of cues to detect intersections. The research project suggested that detectable warnings had a modest impact on detecting intersections since, in their absence, pedestrians with vision impairments used other available cues. The results of this research indicated that there may be a need for additional cues at some types of intersections, but did not identify the specific conditions where such cues should be provided.

Suspension of this requirement continued until July 26, 2001, to accommodate the advisory committee’s review of ADAAG and resulting rule making by the Board.²³ The advisory committee recommended that the requirement for detectable warnings at platform edges in transportation facilities be retained, but it did not make any recommendations regarding the provision of detectable warnings at other locations within a site. The advisory committee suggested that the appropriateness of providing detectable warnings at vehicular-pedestrian intersections in the public right-of-way should be established first, and that the application to locations within a site should be considered afterward. Consequently, the Board did not include requirements for detectable warnings in the proposed rule, except at boarding platforms in transit facilities. Nor did the Board further extend the suspension, which expired on July 26, 2001. Since the enforcing agencies did not extend the suspension either, the detectable warning requirements are technically part of the existing standards again. DOJ and DOT can provide additional guidance on their enforcement of these requirements pending the update of their standards according to these revised guidelines.

The Board will address and invite comment on detectable warnings on curb ramps in its development of guidelines covering public rights-of-way. Those guidelines will be proposed for public comment based on recommendations from the Public Rights-of-Way Access Advisory Committee. This committee’s report to the Board makes recommendations for detectable warnings at curb ramps. Consistent with the ADAAG Review Advisory Committee’s recommendation, the Board intends to address detectable warnings in public rights-of-way before including any specification generally applicable to sites. Thus, this final rule does not reinstate requirements for detectable warnings at curb ramps or hazardous vehicular areas.