Okay, I just joined this thread...so...I'm going to respond to each one in sequence.
First off, thank you for the kind comments about Vanguard products. My response is not about Vanguard products. We're very proud of them, as we designed them based on the absolute, and consistant failure of every other product out there as pertaining to "detectable warnings".
The short version is, we were/are a local (Seattle) company that was asked to install detectable warnings (prior to the suspension in 1994...released in July 2001). Our frustration was that everything that was available....turned out to have any number of flaws (peeling, chipping, fading....ad nauseum).
Today we are a national company providing non skid (not "slip resistant"

detectable warning products in every state, through licensed applicators (see "stadry" comments above).
This remains true today.
That is the end of my "Vanguard is better" speech.
Now, on to the comments...in sequence:
trafficPro:
"The Buttons"...are required (ADAAG 4.29.2 is the law...other options simply don't exist)....and there IS an easier way (one in which I'm not allowed on this forum to promote...however...I suspect you can find me).
Your concerns about womens heels are valid....that is only ONE of the issues with grooves.
Aside from the fact that grooves are not detectable....they hold water...grow moss...it's simply a bad move.
Moreover...it won't meet any standard of detectability.
Remember...the ADA states clearly....any exterior ramp that is designed, built or formed such that it "holds or retains water" is unnacceptable (as per ADAAG)...ergo...any surface texture that does so...is verbotten.
LTAPPJim:
He is correct (see above). By the way...the list of detectable warning suppliers can be found at "
trafficPro:
Keep in mind...DOT/FHWA has/have made clear...the only acceptable "texture" is truncated domes (kinda like Ford when he said in the early 1900's..."you can have any color you want...so long as it's black"

..in short...the only acceptable texture for "detectable warnings" is....truncated domes.
Cincinnati has stated that stamped truncated domes won't fly (and are not acceptable)...they have also alluded to that "glue down" tiles are also not acceptable. New Mexico has rigorously stated similar sections...as have several other states.
Injection molded tiles just don't work.
Truncated domes ("detectable warnings"

are now required on public and private ramps....full width and depth on ramps, 36 inches on "Hazardous vehicular ways", and 24 inches on DOT/FHWA sites (cities/municipalities, etc.).
Be aware...the Federal Access Board has stated...through "Equivalent Facilitation"...the 24 inch standard is acceptable (in lieu of all other standards)...but further..they have stated that they do not have the authority to mandate same....DOJ does.
DOJ has told me verbally that they would (and do) approve this design change as equivalent to all previous (4.29.2) designs.
They won't however put it in writing.
Safe bet: Full width and depth on ramps, 36 inches on hazardous vehicular ways.
If, however, you want to serve the blind and visually impaired community well....use 24 inches (see PROWAAC re: "vibratory zone"

. "Equivalent Facilitation" allows this. (It is also preferred by all agencies).
GeoPaveTraffic:
See me. I have photos of this product fading in less than 16 months (in Seattle...kinda rainy there)...and once fade begins..it's exponential.
COLDDAVE:
I have what you need.
trafficPro:
They all fail. I wish I could tell you otherwise...but...they simply don't work.
I have a better plan.
(See comments above re: Virginia rail from "stadry"

.
trafficPro:
COTE-L....I like this product....I actually like it a lot...however, the April 6, 2002 Draft final from the federal access board states that you cannot paint detectable warnings to cause them to meet the visual contrast.
COTE-L's surface coloring is not a paint...but it's not "integral" as required. This causes the surface to need recoating on an ongoing basis. The ADA states (I'll paraphrase since I don't have the docs in front of me) that "all ADA installations MUST be maintained in 'as installed condition'".....clearly....no one wants a system that requires the city of.....or the county of.....to have to schedule maint.
(I know of a system wherein which this is not required....and...if you email me...I'll tell you what it is).
There ya have it...thanks for allowing me to comment.