Detectable Warnings such as those shown in the photograph above have now become common place, but many facilities still do not have them and therefore are subjecting themselves to a lawsuit.
Some of the problem is that many buildings owners are confused about the use of Detectable Warnings. This confusion is legitimate because although Detectable Warnings were originally included in the ADA, they were soon suspended so that research could be conducted regarding varying tactile surfaces such as grooves, dimples, etc. The research found that in many cases those surfaces were in fact not detectable due to similarities to normal walking surfaces. Finally, in July 2001, the suspension was allowed to expire and Detectable Warnings were again required.
The purpose of Detectable Warnings is warn the sight impaired that they are about to enter a vehicular traffic pathway. The Detectable Warnings do this in two ways: 1) As opposed to other walking surfaces, they provide a very notable change of surface as someone is walking on them and 2) they are brightly colored so that they are highly visible to those with limited vision.
It should also be noted that the sight impaired usually have a heightened sense of hearing; however, with the new gasoline/electric engines that are much quieter, they are making it very dangerous for those with sight impairments. Now there is a real possibility that someone with limited sight may actually walk in front of a moving car in a parking lot and get seriously injured, therefore it’s important that buildings owners install Detectable Warnings that are approved by the State of California at vehicular traffic ways to help prevent this from happening.