I understand your confusion. I have pulled the following information from
several sources (Department of Justice website, Department of Transportation
website, Federal Highway Administration website):

"ADAAG serves as the basis for standards used to enforce the design
requirements of the ADA. These standards are maintained by the U.S. Department
of Justice (DOJ) and the U.S. Department of Transportation (DOT). It is these
standards that the public is required to follow. Regulations issued from these
agencies provide important information on using and applying the standards."

The following information was copied from the "Code of Federal Regulations"
published by the Department of Justice, Revised as of July 1994, and titled
"ADA Standards for Accessible Design" (www.ada.gov/adastd94.pdf):

4.29.5 Detectable Warnings at Hazardous Vehicular Areas. If a walk crosses or
adjoins a vehicular way, and the walking surfaces are not separated by curbs,
railings, or other elements between the pedestrian areas and vehicular areas,
the boundary between the areas shall be defined by a continuous detectable
warning which is 36 in (915 mm) wide, complying with 4.29.2.

4.7.7 Detectable Warnings. A curb ramp shall have a detectable warning
complying with 4.29.2. The detectable warning shall extend the full width and
depth of the curb ramp."

The ADA has said that truncated domes are the only acceptable warning surface.

A new set of "draft" guidelines have been created and are currently being made
available for public comment. These guidelines recommend reducing the
detectable warning surface on a curb ramp to a 24" strip at the bottom of a
ramp behind the curb. The Federal Highway Administration and Access Board have
both stated that the proposed guideline provides "equal or better
facilitation", but neither group has the authority to adopt the new "draft"
guidelines.

If anyone else has any comments about this issue, I would also appreciate more
interpretations.

ADAAG (as adopted by DOJ as the Standards for Accessible Design) section 2.2
states:

"Equivalent Facilitation. Departures from particular technical and scoping
requirements of this guideline by the use of other designs and technologies are
permitted where the alternative designs and technologies used will provide
substantially equivalent or greater access to and usability of the facility."

Both the Board and FHWA (DOJ has a Memorandum of Understanding designating DOT,
and thus FHWA, as the enforcement agency for public rights-of-way) have
determined that a 2-foot minimum of detectable warning at the bottom of a curb
ramp provides equivalent facilitation and, therefore, complies with ADAAG.
Effectice November 29, 2006, DOT adopted the new ADA and ABA Accessibility
Guidelines as the enforcable standard under 49 CFR part 37 (
www.fta.dot.gov/civilrights/ada/civil_rights_5936.html). DOT added section
406.8 to formally codify the 2-foot wide detectable warning.

Standards are not themselves requirements -- they are just measures of
compliance and a safe harbor for designers. The actual text of the title II
guidelines requires that new construction -- and alterations, to the maximum
extent feasible -- to be accessible to and usable by people with disabilities
(28 CFR Part 35 at 35.151). It goes on to say that if you follow the standard,
you are presumed to have complied with this requirement for those features that
are scoped in the standard. But notice that title II (and the standard) also
say that you can achieve the required objectives(accessibility/ usability) in
other ways. This is called 'Equivalent Facilitation'. Both the Access Board
and the FHWA agree that, given the concerns of wheeled mobility users rolling
over DWs and the research that indicates that DWs 24 inches in depth were
highly detectable (as required at transit platforms), installing a depth that
is less than the full length of the ramp can be considered equivalent
facilitation.

Design professionals can make this determination themselves. It is well
supported in this particular case and has not been challenged by DOJ. Most
jurisdictions have been using the 24-inch specification from the draft PROWAG
without difficulty for several years.

The Access Board and the FHWA have both issued statements encouraging and/or
recommending government agencies to an early adoption of the proposed public
rights of way rules. There are many advantages to doing so and the 24-inch
depth detectable warning standard is one of them. In addition, the memo issued
by FHWA (HIPA-20) on May 6, 2002 (regarding the suspension of the detectable
warning requirment not being extended) specifically encourages the use of the
"new" detectable warning standards. In light of these two facts, the use of
24-inch depth detectable warnings is clearly being promoted by the controlling
and enforcing agencies as the preferred design and accordingly should not
present any legal problems.

The department of justice would have the final say. How it stated to me by that
deartment was" We will tell you if you meet the requirements WHEN we take you
to court". Seig Heil

This is similar to my concern. It's one thing for DOJ and FHWA to have an
"understanding". But ADA lawsuits get filed in Federal court, where the judges
may have a different perspective on the matter. The judge may not be part of
the "understanding".

My point is that DOJ may not sue you for a 24" warning, but if you want to
stand on safe ground I think you have to go the full width and depth.

It's not just an "understanding"; even old ADAAG acknowledges Equivalent
Facilitation under section 2.2. In addition, DOT has adopted as its standard
the new ADA and ABA Accessibility Guidelines and added section 406.8 specifying
the two-foot strip as part of the standard requirement. In addition, the DOJ
Project Civic Access Chapter 6 ( www.ada.gov/pcatoolkit/chap6toolkit.htm)
accepts the new standard.

Section 1108.1.4 of the Draft Guidelines for Accessible Public Rights-of-Way
post on the DOJ web site says:
1108.1.4 Size. Detectable warning surfaces shall extend 24 inches (610 mm)
minimum in the direction of travel and the full width of the curb ramp,
landing, or blended transition.

See www.access-board.gov/rowdraft.htm

I see no reason to go the full depth of the ramp.

Dennis, you're misunderstanding my point, I think. The concept of "equivalent
facilitation" has a spotty history as a useful tool in court cases. DOJ is
not the only party that files access lawsuits, and what is acceptable by DOJ
for Project Civic Access may not be as well received if the Justice Department
attorneys are not the ones presenting the case.

A previous post referenced the understanding between DOJ and FHWA. I said that
an "understanding" is not something I'd be comfortable testing in court. The
fact that DOT has adopted the new guidelines was not part of the conversation
at that point.

Mark, city streets are not all covered by DOT. In my view any city that rushes
to use the new guidelines in throwing the dice on whether courts can be
convinced that this is the correct course.

My whole point is that using the new DW guidelines is a risk in many cases. No
matter how good you guys think they are, that's not the issue. Cities have to
face litigants in court and the safe ground is the current enforcable
standard. Anything else is a gamble. And so is trying to convince a court
that your view of "equivalent facilitation" is valid, especially if the
complaining party making a nice sounding counter argument.

Good discussion - nearly all responders have provided accurate information
pertaining to the question on appropriate application of detectable warning
devices at curb ramps. As Dennis Cannon points out, USDOT's (inclusive of its
modal administrations)role is more than just an understanding. USDOT and DOJ
are the standard-setting/enforcement agencies in the area of accessible
transportation facilities. I assume that most attorneys/judges would look to
the DOJ for their expertise in ADA cases, since they are ultimately the
enforcment agency.

All the cities in Washington are using the 24" depth as far as I know. All the
guidance that I have read says 24" is recommended whether you like DW's or not.
I have assisted our FHWA regional office when they do ADA compliance reviews in
towns and cities in Washington. The 24" depth has not been an issue. What has
been an issue is when the DW's are not there and there's not a plan to put them
in place.

Mark, where do you get that I dislike DW's? Nothing in anything I've posted
says anything remotely like that.

The fact that a lot of cities in Washington are using them does not change my
point.

The current 'standard' as adopted by the USDOT is 24" deep from the curb line
and the full width of the curb ramp. This was adopted for transporation
facilities on Nov. 29, 2006. For public rights of way and other transportation
facilities (bus stations, rail terminals, airports, etc.) this is the new
standard. The USDOT is the regulatory agency under the ADA for transportation
facilities (just like HUD for multi-family housing, DOE for schools, etc.)

I'm glad I found this site! And what's even better is that I get to follow
Dean with a question.
We (the County) just finished retrofitting a few miles of sidewalks into
neighborhoods where elementary schools just popped up. In some locations we
were forced to put in 5' sidewalks but wherever we could we built them 6'
wide. The detectable warnings were a standard 5' wide leaving 6" on each end
in about 50 locations. The FDOT Inspector rejected the job based on the
detectable warnings needing to be the full width. The project manager
estimates that the "fix" would cost nearly $1000 each or $50,000.
I just spent some time with the president of the National Association of Blind
Veterans in Orlando at the Pro Bike/Pro Walk Conference. Walking on the
streets with him was, pardon the pun, eye opening. Some of the things he told
me like needing to be on the traffic side of the light pole so the left turning
vehicles could see him was something I would have never thought of. He told me
that the "sweep" of his cane was about 36". I asked him if it would be at all
possible for him to walk past the detectable warning on the 6" of concrete on
either side of the dw's. He said no and thought it was ridiculous that we were
being withheld payment. I told him how much the fix was and said that the
cheap fix would be to saw the concrete down to the 5' width at the warnings or
just break the additional 6" off with a sledge hammer. I think that we have
met the usability objective and any "fix" would be an opportunity for the press
to capture how expensive it is to accommodate the blind.

I hate to be the stick in the mud , but yes you can walk past the DW panels if
there is a 6 inch width on either side. If you are in regular stride it is
easy to step on an area that has no Truncated domes. I agree with the FDOT
inspector on this one. Full width of the walk is the rule.

I have a couple of questions about this project. I support the FDOT inspector
who would not accept the detectable warnings that are less than full width of
the sidewalk. A small gap on each side of 2" may be acceptable, but 6" would
not. 6" is large enough for a foot/shoe to step there and miss the DW
entirely. I have to wonder why the contractor chose to use a single product
size for all conditions when various material sizes are available. I would
also disagree with the $1000 per curb ramp 'fix'. I'm guessing that the plan
is to demolish all the curb ramps and replace them. I'm sure there is a
simpler method - grinding the concrete to allow a surface-applied treatment,
etc.

I hesitate; however, I too must side with the inspector on this one. Full
width is full width. I hesitate because the width of the sidewalk is
definitely above and beyond any accessibility requirements. I see the benefits
of having a wide pedestrian path-of-travel and applaud the city's efforts for
doing so, unfortunately, a 6' width must have a 6' wide dome application.