Truncated Domes


City and County of Denver

Truncated Domes vs. Denver Standard

As used with Pedestrian Curb Ramps



On July 26, 2001, the 10 year suspension to the provision in the Americans With Disabilities Act requiring the use of truncated domes as a detectable warning at curb ramps was lifted.  As of that date, all curb ramp construction was required to utilize truncated domes, no other alternative was acceptable. 




The City of Denver has a long history of accessible construction predating the requirements of the Americans With Disabilities Act.  Those older ramps were not constructed using directional joint patterns or contrasting colors, but they were built to function as a means of getting mobility impaired people safely into and out of a roadway at a proper pedestrian crossing.  They closely followed the provisions of the Architectural Barriers Act of 1968.


The Americans With Disabilities Act was approved by Congress and signed into law in 1990.  Title II of the ADA, covering state and local governments, was published in the Federal Register July 26, 1991, an important date in the mandate of the use of truncated domes for detectable warning.  The provisions that apply to the installation of pedestrian curb ramps, 28 CFR §35.151(e), became effective for all roadway and sidewalk alteration or new construction on January 26, 1992.