Law Office of Rick Morin

(916) 333-2222

What are Truncated Domes?

ADA compliance guidelines are in constant flux. One example of the ever-adapting rules is truncated domes—also known as tactile paving or detectable warning surfaces.

Truncated domes refer to the (often yellow) set of raised bumps on a pathway or platform. Truncated domes alert visually impaired individuals of surface changes and other potential hazards.

If you are a business owner with truncated domes installed on your property, you may still be in violation of ADA standards!

A History of ADA Guidelines for Truncated Domes

Beginning in 1991, ADA guidelines required the domes to have a nominal 0.9-inch diameter, nominal 0.2-inch height, and nominal 2.35-inch center to center spacing.

Both the Federal Code and the State of California Building Code (CBC) changed in 2010. The California state requirements then specified that while the base diameter must be 0.9 inches, the top diameter must be 0.45 inches. The Federal Code also newly specified a 0.65-inch minimum base to base spacing between adjacent domes. This was in addition to the already existing center-to-center spacing requirements.

Even further, the 2010 CBC change required truncated dome sections to occupy the entire length and width of a curb ramp, doubling the amount of panels previously required.

Where are truncated domes required?

In California, the detectable warning panels must be installed in the following situations:

  • Platform Boarding Edges
  • Curb Ramps
  • Islands or Cut-through Medians
  • Bus Stops (between the pad and the road)
  • Hazardous Vehicular Areas: “If a walk crosses or adjoins a vehicular way, and the walking surfaces are not separated by warning 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.” (CBC 11B-705.1.2.5)
  • Reflecting pools: “The edges of reflecting pools shall be protected by railings, walls, warning curbs or detectable warnings.” (CBC 11B-705.1.2.6)

Individuals do not have to be visually impaired in order to file a lawsuit regarding the truncated domes. If the spacing or size of your truncated domes is not in accordance with the CBC, those who are mobility impaired can claim that the domes are acting as a barrier to their entry.

As you can see, ADA compliance is tricky and full of traps for the uninformed.

Due to the increase in ADA lawsuits filed in recent years, business owners should verify that their detectable warning systems are up to code.

I represent business owners and property owners throughout the State of California that are faced with ADA lawsuits. Contact my office at (916) 333-2222 if you have been served with an ADA lawsuit or ADA demand.